I honestly don't remember on which site I read this, but there was a recent article about autogynephilia which gave me some insight. While a huge part of the turn-on is becoming a 'woman' (and thus a dehumanized sexual object), it is also a very important part of the fantasy for them to receive external validation.

Straight, bi, and pan women are already attracted to males (which they are and know they are), and we all know a lot of men will screw anything with a warm hole, so what could possibly be more validating than bagging a lesbian? That clearly must mean they are viewed as an actual woman, right?

Reading the article gave me a light bulb moment that may have been obvious to others and maybe I'm just late to the game. It's not even really about lesbians, it's about porn sick completely self-absorbed mush-brains of these men. It is about having the world validate their fetish. Which is why they have no issues trampling over and ignoring women, because women are only the fuck objects they wish to become to begin with for their depraved sexual gratification - but not really, because they don't want to give up the age-old male past-time of threatening women who don't want to sleep with them with death and rape. And what kills me is they can't even grasp, have absolutely no sense, of why this is fundamentally different than female human behavior, speaking in broad strokes of course.