My running theory is most of these people are queer to some degree. They end up hating women because they don't have the communication skills to express what they want out of a relationship. When they become unfulfilled then they blame it on the person they think is supposed to be fulfilling them. Sorry boys if you want your SO to peg and domme you you need to tell them.
While I've experienced some pretty horrible misogyny from some gay men, I don't think this is even close to being accurate (and is one more way to make queer people the enemy). There are plenty of straight men who hate women but still want to fuck them. Those things can coexist, unfortunately.
You know, it wasn't that long ago when it was pretty common for closeted gay men to overcompensate at hiding their gayness to the point of sexism and homophobia. People like that do still exist. I can imagine some incels very well being queer, and acting out either in compensation or confusion and frustration over their own feelings having not come to terms with their sexuality.
That could be a cute romance story. Two incels bond over hating women and SJWs. They get together to play Valorant or browse 4chan in bed together while posting gore. They turn to each other and speak in green text and kiss.
It really would(n't) be but that takes some self awareness and reflection many of them simply don't have the skills to achieve. I'd assume once you have achieved that amount of self awareness you stop hating women but maybe I'm being hopeful.