Because most of them pretend to be bi because they either feel that they won't be as hated as if they say they're gay; I don't think that all the bisexual people are lying but many of them are hiding behind that mask to not feel completely rejected which is what give the bi people a bad reputation or make people think that bisexuality doesn't exist.
And if you ask me that if I'd date a bi guy, I probably wouldn't.
Not really in my experience the only ppl who have thought I needed to pick one were other gay ppl, straight ppl do not care
This is kinda true. Not to segregate the gay community into blame, but a lot of our community refuse to acknowledge bisexuality at all as a serious sexual identity.
Actually, I have very often made the experience that bisexual men try to use it as an advantage against gay men "cause they have the option" if you are not playing by their rules. Not only once, actually every time I meet a bisexual guy and I'm always like "Get the **** outta here. I don't wanna hear your ***** stories".
Hell, even a 16-year old friend of mine got pressured by a bisexual guy to have finally analsex with him asap otherwise he would leave him for a woman. I had some serious talk with this dude, that did not end up very well for him.
So, I think it works both ways. Gay men basically don't care about bisexual men. They are only interesting if they are attractive. And bisexual men feel disrespected because nobody takes them serious.