Being bisexual myself since the first dawning of puberty, I confess to being still confused about it.
Similar to very many people, male and female, I find the sight of two women tenderly kissing a huge turn-on. Yet while I like having sex with both guys and gals, the sight of two guys kissing one another is a maggot-gagging turn-off for me. Why? I have no idea. It's not a decision or a choice on my part, it's a completely subconscious response from some part of my brain below my awareness. No, it's not logical Mr. Spock, it's just the way it is for me.
I suppose the issue of "do we care" is a function of the scenario. I have an openly gay flight student whose hunky bones I would like to climb. But my purpose is not to seduce him or to straighten him, it's to teach him to fly an airplane. In that context his sexual orientation is a complete irrelevance. Perhaps, in fact, his exclusive gay orientation makes him sexually safely off the menu and so I feel no sexual pressure in any way from him.
On the other hand I have a female friend who is giving all the signs of being bi-curious, and whom I suspect is teetering on the edge of coming on to me. That matters to me, because despite my own inherent willingness and even desire to share that precious joy with her, I am in a committed exclusive relationship and am not free to go there with her. So yes, I care in this case.
As a girl who likes to shoot icewater up her bum, I have no grounds to hold any opinion about anyone else's sexual practices or predilections. But to the extent someones sexuality involves or means to involve me, it matters a lot.
Hugs,
Diane