I don't like music made after 1980
...and I'm only 22. It's pretty much always been that way. I remember when I was a young teen that I tried to get into the music that my classmates liked, but after a while I stopped pretending that I enjoyed it and stuck to oldies.
There are a few exceptions - "Mad World" by Tears for Fears and "Does He Love You?" by Rilo Kiley come to mind - but they are the exceptions rather than the rule.