Asexuality does exist, however it is a much smaller portion of the population than a lot of them claim. One thing I've noticed amongst the people I've met who identify as asexual is that... every single one of them has been very unattractive. And I do mean every single one. Almost like their supposed asexuality is a defense mechanism because they know they're perceived as unattractive. "Well I'm asexual, so it doesn't matter anyways!" I might be more inclined to believe an actual attractive person was asexual, but I have never seen that. Other common traits amongst "asexuals" is that they have been perpetually online pretty much their whole lives, and live with their parents well into their mid to late 20s and onwards. They also tend to be mentally stunted, for lack of a better term. So my guess is that for many if not most of them, it is not actually their legit sexuality. It's not genetic, it's just what they call themselves for a variety of reasons that exist as comorbitities with the general inability to get a partner.