Hmm. While I do slightly agree with your statement. I believe it's more so for the player choice than anything. I mean you the player can just ignore your characters crush.
While still going after what you want. But, I do understand where you're coming from. And it is weird. If you choose to make your character straight or gay.
Then that should overwrite your characters likes and dislikes. But! I personally find it funny when a straight guy or lesbian girl ends up blowing me on a coffee date.
It's like... Wait you only like women? Why are you on this date with me? Wait why are you laying your head on my lap? Why are you sucking my dick when you don't like guys?
But yea besides NPC's I never noticed that. Because I play Bi characters. However, that might be one of the things that get addressed in a later update.