He make movies about perversion.
His famous films are glorifications of perversion.
Criminals, murderers, gangs, etc all populated by people who are the bottom of the barrel, sociopaths, people who don't know how to solve problems, and so on. They are weirdly "good" but that's even more perverted.
We "like" his perverted characters and films. We like how they murder people, or are "psycho" and that means he's a seductive little pervert. Someone like him probably has induced mental illness into people watching his films. That could mean that you want to emulate his characters and do or don't but still he made you want to.
What has been the influence of superheros?
That's a genre about human ideals, the best know of behavior, overcoming oppression, being humble even when you don't have to be, and the genre is almost secularly religious. They are stories about awesome people that the population has enjoyed for almost a hundred years in some cases.
Batman and Superman are OLD characters and people still, of all ages, admire Superman. That's because YOU know that YOU are Superman inside. You would do the same things if you could.
Art is supposed to be art if it moves you. His art moves perverted feelings in people and comic books stories do the exact opposite.
He sees the character in Taxi Driver as a Batman, but really he's an insane social misfit who murders people who are criminals after he failed to shoot the president. That's an insane pervert. Batman is a self-sacrificing character who decides to help people through total dedication and doesn't murder people. That is how broken people ought to act and that's inspiring. His work is demoralizing due to its perversion.