I do think that the whole, "masc for masc" thing is probably, on some level, for many people, some kind of expression of internalized homophobia.
Here's the thing though - we have to be humble when it comes to individuals - Does it make sense to inform Bistud that he needs to, "check his masculine privilege"?
Let's say, for the sake of example, you are correct and Bistud is a homophobe. He is probably not aware of his own bias. How do you think he will respond to you calling him out?
The problem here, I think, is mind reading. It reminds me of when other people inform me that my being gay is a choice . I think many people have experienced some degree of bisexual attraction or at least, have been able to imagine themselves in bisexual acts and so for them, it seems like I should just choose to ignore my same sex attractions (after all they have probably done so themselves). The problem is; I have never been attracted to a girl in my whole life. Like literally never. I might be able to have sex with a girl if I closed my eyes and fantasized about a guy the whole time - what kind of choice is that?
People will almost always get offended when you try to mind read them. If you guess right, they will probably just get defensive and you will find yourself in a flame war. If you guess wrong, they are likely to feel stereotyped and get all bent-out-of-shape over that.