You're not taking into account the opportunity cost.

Let's say that I'm never interested in playing checkers. I am interested in playing chess, Connect Four, or Chinese checkers, but regular checkers have zero appeal.

I only have so much free time and so much energy. My life stresses me out for a variety of reasons. I want to use my limited free time and energy for things that actually rejuvenate me and give me more energy and happiness.

And the world keeps wanting me to play goddamn checkers. Every person I've ever dated wants to play checkers with me. There are weekly checkers tournaments and everyone you know is into checkers. People actively give you a hard time and say there's something wrong with you if you never want to play checkers.

Under those circumstances? Fuck checkers. I will date someone who wants to play chess with me, or someone who is okay with playing checkers with other people. But I'm not going to force myself into playing checkers when my personal happiness would benefit so much from not playing checkers, especially in light of the hostile environment.

But that doesn't mean I started from fuck-checkers. It means I started checkers-disinterested. The part of me that is part of my identity is checkers-disinterested, not fuck-checkers. (Unless I get so tired of all the checkers advocates that I go full swing into the opposite.)

Also,

1) Antisexual would imply hostility toward other people's sexual behavior. Asexual doesn't.
2) Attempting to redefine anyone else's identity from an external perspective is pretty offensive.