Oh, come on! I hear that crap ALL the time. "Old rock".....
Good music is good music. It shouldn't be defined by what's "now", "new" or "hip".
I listen to almost everything. If it's good, it's good. Suddenly "Master of Puppets" isn't any good because it's 20 years old? What then would you say of "The Wall" or the "White" album?
Hell, I even listen to Big Band/Swing every now and then. That stuff is still great!