I appreciate you pushing folks that just gave short answers to actually find the answer within themselves. Anyone can say things like "she's only popular because the media says so" or whatever but why do you personally not enjoy her brand of music?
I am not a swiftie per se but I can get into some of her stuff because it's a bop. I'm 42 if that matters. Her demo is mostly (and has been since her beginnings) young girls to early teens. As she herself has grown as a human, so has her music. Just like Miley. Just like any child star that comes out better on the other side.