I think the idol industry in Korea especially makes it an environment where male idols can become that way. Money, fame, success gets to their head. They've got an unstoppable crazed fangirl force that will back them up almost to no end. They can pay off police to get out of trouble. Toxic fangirl culture is unhealthily obsessing over idols and idols intentionally feed the delusion that they're your boyfriend and whatnot. It's not too surprising that male idols grow up and lie to and manipulate girls, and don't treat them with the respect and dignity of another human being.