Aside from what others have been saying. It may also be something to realize that giving music a single listen can easily cause you not to like it, and given that we've heard all of this crap so many times we know its crap (excuse my coarse language). But they on the other hand have not heard the good old fine stuff and don't understand (maybe some day they will, but there brains will shrink before that age-- not really just poking fun).
I think its important to mix the new with the old.
Personally I think Metallica has some really awesome stuff, but for me most of their stuff is just OK. My favorite band may be a band most people don't really like or know beyond one or two of their "middle period" albums i.e. REM (Blink 182 is actually tied with them for favorite, I just can't choose, just can't choose)
I also love Radiohead, Beatles, Zepplin, Billy Joel, Green Day, Jack Johnson, anime music, Beethoven, well I could go on and on, you get the idea, there are still a lot of great bands out there, whether or not you personally consider them timeless. You should give some new bands a try, but like others said it is impossible to keep up (damn them, damn them all) especially if you spend a significant time watching anime videos
Someone should may a video based on Bush's Golden State CD, Bones and I think "the ones we love (name?)" (well it begins speed kills coming down the.... you get the idea if you heard it you would know)
One of those two videos (maybe to Tenchi or various, don't know)
Sorry for the out of topic digression.
Alex