The problem with religion is that many of them have actual bits written in about hating anyone who is of any other religion, or who doesn't follow the rules that that religion prescribes. The problem of othering rather than acceptance. And since Men wrote the books that contain those religons, yeah, those problems have been created by men. (men-human, but in this case literally men)
Being atheist doesn't automatically make someone an intelligent rational person. He's an idiot obviously, IMO. Why does that need an explantion?
I'd guess he has some deep psychological issues... he makes a lot of videos seeking attention. Perhaps he gains some pleasure from the pouring of hot oil over his genitals and he is being an exhibitionist with that? Perhaps he is into the trance like "vision" states that can be achieved through pain which is also common among religious fanatics who do things like knee for hours on a wooden strip. *shrug*
You don't have to believe in 'god' to investigate those things... just ask any body mod suspension group.