In my opinion, "music" today isn't music. It's manufactured more than played.
This is just my opinion though.
Yes, I'm one of those people who listens to old rock and criticizes those who don't enjoy it. I have a good reason though, because those people who mind their own business and simply don't prefer my tastes are doing nothing wrong. It's the people who speak out and talk about how new music is much better.
Basically, if you're criticizing me for my tastes, I'll criticize you for yours. You're perfectly fine if you just don't enjoy certain music. In fact, you're better off with your own opinions than trying to "conform" with certain groups of people. The music you like shouldn't be a status symbol. True, most of my friends like the same music as I do, but I'd rather have someone truthfully say they don't quite enjoy rock rather than have someone pretend to like it just to be cool...
Also, OP if you're trying to get into some good rock, have you tried Iron Maiden? They just came to mind as I was typing up this post, and I just enjoy the sound of their music.
Otherwise, stick with your likes and quit being self conscious of them.