This is a pointless rushed thread. I considered making it hours ago but decided against it because I've mentioned these ideas in other posts, if not threads I've started, and part of it is preaching to the choir or reiterating something that most people would probably assume about some of what drives anti-gap relationship prejudice if they were brutally honest with themselves.
The first point is that normalizing an age-gap preference (but not necessarily a mere attraction to relatively young men/women, which is something different than either a preference or attraction for/to younger people) contradicts the monogamous ideal that is important to most people and I don't think that you can reconcile the two. Under the monogamous ideal that I have in mind: 1) you're supposed to be attracted to your partner until death (there's a scene in Roots when Matilda comments on how old she must look to Chicken George after they've spent so much time apart and he says something like, "woman, when I see you I don't look at you with my eyes, I see you with my heart," which is sweet because if you 'love' someone in any way that I find meaningful you won't stop loving them when their appearance changes but love is not attraction. Most people aren't going to be brutally honest about the fact that they eventually lose their sexual attraction to their partner, at the very least; if they still want to have sex in old age, their partner will almost certainly not be their ideal in terms of their appearance which does matter; relative to attraction I mean. Libido is separate from emotional attachment and compassion, either of which is the kind of 'love' I'm talking about when I say that I could honestly tell a woman that I would love her even when she's old and wrinkled, sex creates an emotional bond and emotional intimacy but you don't necessarily love your partner less when you're not in the mood for it) and 2) you're supposed to be attracted to your partner alone. This doesn't apply to everyone who values monogamy (e.g. some couples will talk about which celebrities they find attractive with each other without any kind of insecurity or unrealistic expectation that their partner will never find anyone else attractive) but I think it's the general sentiment, neither of these two points I'll make can account for all of the stigma.
From this perspective, other people won't find it as emotionally harsh as I do to tell people that they should be attracted to their own age group (because you should be attracted to the person you've committed to grow old with) and that you shouldn't be attracted to younger people (because you shouldn't be attracted to anyone other than your partner, so why do you 'need' young women?). A preference for relatively young people is inherently 'unromantic,' depending on how we use the term, not in the sense that it excludes what I might call 'romantic attraction' to the people you're sexually interested in but in the sense that it's brutally unsentimental, it's not going to appeal to someone with an idealized romantic view of 'romantic love.' If you openly tell the world that you have a preference for children under 11, 11-14-year-old preteens/young teens, 15-19-year-olds, people under 25, people under 35, and so on you're telling them, effectively, that you're not interested in a long-term relationship (or at least not an 'until death' relationship), at best you can do serial monogamy but not the 'until death do us part' ideal. If you're trying to normalize an age-gap preference you're arguably trivializing the sacredness of 'romantic love.' The general standard today is that people are supposed to find 'the one' and grow old/die with that person, that should be their goal even if divorce can be justified, and this underpins a lot of the anti-promiscuity rhetoric (even though rejecting it doesn't have to imply full-blown 'promiscuity'). A lot of people won't accept that some people are just never going to be interested in a committed exclusive relationship, the only sex that they 'can' realistically have is casual sex, but anti-promiscuity people (depending on how indiscriminating 'promiscuous' people are or what exactly we mean) don't seem to understand that not everyone has the personality-wiring for what they consider to be ideal (stop hoing around, pick one person, settle down, have a committed serious relationship). You could accuse me of calling the kettle black because I think that 'promiscuity' under the right mindset (wanting happiness for all people, indiscriminately) would be the ideal but that's another topic.
My second point is that female anxiety around aging seems to be responsible for a lot of the taboo, women are not the only ones who suffer from mid-life crises, it already bothers me that body dysphoria is typically presented as a female struggle, but it does makes sense to expect that they will generally suffer from a mid-life crisis or 'age dysphoria' to a greater extent than men will (although I don't think that the struggles of individuals hold more or less weight based on how statistically represented whatever group they belong to is in terms of whatever they're struggling with). It's ugly to say and part of why I initially decided against posting what would repeat something that I've already argued countless times in other threads, and male sexual attractiveness also declines with age, but female sexual attractiveness declines to a greater extent than male sexual attractiveness because, under normal circumstances, men at least remain relatively fertile until death (some middle-aged women are much more conventionally attractive than average middle-aged men but I mean in terms of statistical trends. Estrogen is a big part in what makes women sexy to most teleiophile men, it starts to decline when women are perimenopausal; maybe even to some degree as early as 25 but it's on a whole different level when they're perimenopausal and their ovaries are starting to run out of viable eggs which is what prompts the transition to menopause/menopause to begin with. Apparently, loss of fat in hips and thighs makes them look less curvy, estrogen plays a role in smooth skin and shiny hair, the loss of estrogen is why men tend to have the advantage after a certain age because it's apparently really beneficial for heart health, the immune system, etc.). There's a certain threshold of unattractiveness where it doesn't matter how much more unattractive you are if you're not attractive enough to have access to any given person but generally older men will or would have more sexual/romantic opportunities than older women in a vacuum or when we're comparing apples to apples. Statistically, women seem to be the primary enforcers of the age-gap taboo, especially or at least when it comes to age-gap relationship between legal adults (people whom everyone thinks are cognitively developed enough to be held accountable for breaking the law so the fact that the argument switches from 'can't rationally consent,' when it comes to minors under 16, to 'power imbalance' seems to suggest an underlying motive that has nothing to do with exploitation, although some people think that younger adults can't consent to a relationship built on a power imbalance because it supposedly involves a power imbalance and not because they aren't cognitively developed enough. Most people also have no problem with 16-18-year-olds having sex so unlike with 7-year-olds, the idea isn't that they're just not 'ready' for sex or that it's inherently traumatizing for them, it's only a problem depending on the status of their partner. If heroin hurts people the identity of the person who sells you heroin is irrelevant).
I've mentioned men being biologically adapted to fertilize egg cells which requires ovulation which requires being both pubescent/post-pubescent and pre-menopausal because instead of being based entirely on a straightforward moral argument (i.e. yes, it's normal for middle-aged men to be attracted to teenage girls but a good man won't act on that attraction) the stigma relies largely on the idea that it's deviant and abnormal for older men to be attracted to girls/women in their teens and twenties which is at odds with biology because an attraction to 'girls'/women in their reproductive years; a preference for women under 45 (when menopause is no longer considered early or premature), under 40 (when perimenopause is no longer considered premature although menopause in one's early 40s is considered early) or even under 25 (when egg quality is at its highest and various medical risks with pregnancy are at their lowest, at least if we're talking about girls who are at least 15 or maybe even 16 or 17) matches the biological function of maleness itself (the 'point' of sperm is to fertilize eggs, the 'point' of a penis is to implant sperm into a woman's vagina) so we should expect average men to be attracted to girls who are 14/15 and up at least (15-year-olds 'always' menstruate in the absence of malnutrition, high stress or some kind of medical issue). The pretense is that normal and/or moral men lose attraction to teenage girls/women in their 20s once they reach a certain age which is delusional above and beyond any moral issue that I have with stigmatizing a potentially harmless source of happiness for two people.
Even many young women sensibly realize that they will not always be young and might feel that they have a vested interest in contributing to a culture that discourages older men from pursuing or just being open to intimate relationships with young women to eliminate competition with younger women when they reach a certain age. This sounds like such a red pill thing to say but studies suggest that women, on average, are more sensitive to rejection than men are, they are more likely to take it 'personally' (I can't find the section in some old college textbook I have that discusses this, I planned to mention some other average gender differences although frankly the textbook rubs me the wrong way because I think it engages in essentialist stereotyping).
I have wasted a lot of time on this. No more time to do what I planned to.
The last thing I'll add is that I don't know what people expect people who aren't attracted or very attracted to the members of their own age group to do about that. Why is it so obvious that attraction is not a choice when it comes to being gay (with left-leaning people, at least) but people can't apply that exact same logic to the creepy old guys who want to date 20-year-olds who will have them?