I think that's a bit of an oversimplification. I used to identify as asexual when I was younger, and I can tell you first hand that the hypersexual culture people (mainly liberals and kinksters) have created was a big part of the reason. Growing up, all my friends and a large chunk of other kids I knew were all pro-kink and "sex positive", which has really just become such a toxic culture. Like being seen as "sex negative" or a prude is practically seen as a character defect. And while kinksters say that "vanilla" is just a neutral term for non-kinksters, it really isn't. I've pretty much only ever heard my friends and other kinksters use "vanilla" as a condescending or mocking term.

It's actually downright disturbing, because I've even witnessed my friends mocking each other for not being into a particular kink. If one of them would be like "Yeah, I like [insert kink A here], [insert kink B here], but I'd never do [insert kink C here]." and the others would mock her like "wow you wouldn't do [insert kink C here] lol you're so vanilla". It's pretty sad to watch young women mocking each other for not wanting to do certain painful and/or degrading sex acts. But that was the norm for me growing up. I thought my friends represented the majority. I grew up listening to them talk about their kinky sex lives, and I thought I was the one who was abnormal and different. A lot of younger people are being made to think that not being into kink or not being promiscuous makes them abnormal, so it's no surprise to me that a lot of people are calling themselves "asexual". It's almost like asexuality is a shield that lets you opt out of the toxic "sex positive" culture. For a lot of young women these days, it's becoming more normal for them to be expected to like anal and choking and shit like that. If you're just a normal straight chick saying no to anal/choking/whatever, then you're just a boring vanilla prude who's probably secretly conservative and "sex negative". But if you're a "hetero-romantic asexual" chick saying no to anal/choking/whatever, then it's suddenly ok. It's just a normal and totally valid part of your queer asexual identity.

So while this stuff is annoying and ridiculous, I think a lot of these people probably deserve a bit more sympathy. Not all of them of course. Some of them are just id'ing as asexual to be special. And tbh any dude who calls himself a "hypersexual asexual" is probably just a creep who's trying to make himself seem less threatening. But I think there's also a lot of closeted LGB people and other just confused young people who legitimately think they're different from most other people.