Brains have to have repeated exposure to a stimulus before they find it pleasurable. This is why you may need to try a new food a few times before you develop a liking for it, and the same goes for new music genres.

If you purposefully go out and listen to new music, you'll quickly get accustom to the sounds of new genres. On the other hand, people who are not in the habit of trying new things never train their brain to enjoy new types of music.