I agree that sort of justification often feels protective. Like it’s easier to say “I can only get off to stories of closeted men having intense sex and feelings for one another in order to escape sexism” than “I’m a pervert.” And depending on how a person feels about this phenomenon, that’s how they’ll categorize the kind of women who participate in it. If they want to be mad about it, it’s straight women (who are therefore committing objectification, fetishization, appropriation), and if they want to defend it, it’s queer women (and therefore responding to trauma, surviving a sexist world, subverting something). But I don’t really see how having this sort of sexual fantasy is suspect if you’re straight but virtuous if you’re gay or bisexual.