I agree that these weirdos aren't leftist, but I don't think many are genuinely "alt-right" or hold any true political beliefs either. Maybe some start out with certain political beliefs that cause their initial extreme fetishes to lean a certain way, but by the time someone is talking about BNWO & gooning on twitter all day, it isn't about politics. They seem way too obsessed with the coom and the politics are just window dressing. It just has to be something extreme and socially unacceptable. They can sexualise anything like that. I think that is why you find so much crossover between extremely socially unacceptable fetishes, like incest, zoophilia, loli, pedophilia, forced-feminisation, anti-white, and anti-black fetishes.
Look at CeCeFem, he was really into the black new world order stuff but then would pretend to be some nazi anime character force feminising men. I don't think it is because he was actually a nazi with a humiliation fetish who thought of blacks as animals, but instead it was because he was so porn sick he couldn't get off to anything but the most extreme stimuli. That's how he could context switch between all of his fetishes, which if he thought through the implications would be contradictory.
GoonClown was similar, he was into everything extreme and vile to normal people. He was specifically into pedophilia not just because he was attracted to kids, but because he was attracted to the idea of ruining something other people wanted to protect. He was into turning other people into pedophiles too, because he was sexually into being evil and vile.