I am that guy who was always in women company (ever since 16, and I am 37 now) and almost never did hit on them. I was just much more interested in what women say, think and do -- compared to 99% of my male peers who were nothing more than testosterone-filled stupid machos.
My evidence is of course anecdotal, but from what I've seen, men have much less desire watching man-to-man action. It's related to many's fear of "turning gay without knowing it" (it's a funny concept but it's extremely common) and very often it's about them looking less manly if they don't show active interest in women... (A lot of men are really weird and kind of stupid in that regard.) That being said, me and many others who aren't ashamed of openly discussing sex are still not interested in gay action simply because it doesn't sexually appeal to us.
As for women, and when I asked them why do they watch gay men porn, many have told me that they believe only a man can know how to please a man to 100% and that they want to better educate themselves on how to be better in their sex life... and they might actually have a point; I've heard from several gay men that no woman's blowjob can ever hold a candle to one that a gay man can do -- I personally believe that to be an exaggeration but I think they're on to something there.
And finally, a lot of girls and women in my life have admitted to being interested in lesbian sex but are afraid due to social stigma and them being extremely vulnerable if they start actively looking for a woman sex partner. My own spouse openly admitted she'd f_ck a woman if she found one willing to do it. Strange thing is I wouldn't perceive that as cheating. I believe my S.O. is correct when she is saying that men think their girls cheat on them only if there's a penis involved.
That, plus hundreds of convos and experiences I've had in my life makes me think that women are innately bisexual while men are, most of the time, hetero-sexual.