I don't really get it either, it's mostly just a looks game. The guys are all effeminate pretty-boys and the girls tend to be overly sexualized. As for the music, I'll take some of it over modern pop but it's still not my jam. Personally, I find J-pop significantly better as it's more diverse in sound and less about the looks game.
Honestly, when it comes to Korea, I'd much rather watch K-drama than listen to K-pop.
