In my experience, it depends on if they genuinely hate all men or not. When you see the opposite gender as an enemy you need to defeat, you stop seeing them as people. From there, it’s easy to apply that toxicity to other people of your gender that you see as traitors to your cause. You start to judge everyone by their adherence to gender roles, even if you see yourself as smarter than others who uphold the patriarchy. That is the nature of an incel regardless of if their gender.

That said, I anecdotally find that sapphics are rarely incels, even if they get no bitches. It’s easier to not be consumed by your resentment of men when you don’t even need date them (note, that this is distinctly different from political lesbians who are only sapphic for ideological reasons; those people are trash). Even if one casually thinks all men are trash, they aren’t forced into conflict with men unless those men approach them first. I suspect it’s the same with gay men who are lonely; even when they are misogynistic, it’s not as much of a problem.