Isn't the answer obvious? It's because you have bad taste. You've probably been fed a lot of shitty music before, so it's not hard to adjust to slightly shittier music. That's what happens. You've listened to so much shit that you can't help but go lower. Would you expect some random idiot who listens to rap and pop music to suddenly gain an appreciation for Tchaikovsky? No. Would you be surprised if that same person started listening to trap music? Probably not.
It's like taste in food. If you're fed McDonalds all your life, you're likely going to be willing to try other shit chains like Burger King and Wendy's. If you grow up eating real food, you're not going to go out and buy a $1 hamburger unless you're broke.