It’s because he’s a good looking white murican wrestling stud, the type of dude who either bullied and/or didn’t give the time of day to 90% of UFC fans. The UFC fan base has always been made up primarily of self loathing middle class murican kids who got bullied in HS by guys like Bader. That’s why they root for someone like Mousasi (who stinks) instead of someone like Bader. Makes them feel not only “cultured” but also like they’re “getting back” at their bullies.
If you’re a blonde blue eyed good looking athletic Murican male, you’re always going to be a h*te magnet.