It is victim blaming, we are not the reason homophobia exists or that people become extremely homophobic. It is not oppressed people that cause their own oppression, we don’t in some way “deserve” it.
Some aspects of the identity of sexuality may be related to physical and things we cannot control, but at the end of the day it is an identity. If they do not see themselves as gay, they are not. It is not for you to assign an identity to someone, even someone you don’t like. Even if someone might identify as gay outside of these power structures, in here they aren’t. Even if they would be gay, they participate in our oppression because being straight is beneficial to them, not because they “are secretly gay”. If they did homophobia because they were “ashamed” it wouldn’t be helping so many of them get into positions of power
There’s a certain paradox at play here. The argument has long been, sexuality and gender identity are innate, you’re born that way. It’s a useful framing both because it’s an absolute reflection of gender and sexuality on a personal level, but also moves LGBT status into the realm of intrinsic characteristic, similar to ethnicity or national origin.
But people chose what’s more socially conducive over their innate characteristics all the time. A cop can hate what they do for a living all they want, they’re still a cop at the end of the day. So from a social standpoint, the Larry “wide stance” Craig’s of the world are straight. And historically this has been a thing, societies in which people (mostly men) having same-sex intercourse is accepted, or at least a blind eye is turned to it, but they’re still expected to maintain a heteronormative household.
There’s a rough analogy with race here. Much as the personal aspects of race are recognized as separate from the systemic aspects, personal sexuality and social sexual identity are separate. You can’t choose the former but you can choose the latter.