I think most of the explanations fail to account for a very important point: music doesn't exist in the abstract but comes with a setting, a context and a community. You don't just listen to music, you experience it. Whether it's an opera house or a jazz club or a rave or a rap battle or a dive bar, all music comes with an associated experience. It can be hard to truly 'get in' a genre and understand why people like it if you can't experience it the way most people who listen to it do.

I think the reason many people get stuck with the music they listened to as a teenager is because their most intense experiences involving music occured when they were teenagers. Then they move on, and if they don't obsess about music, they won't have stronger feelings about the new stuff.