It's okay if you have no musical tastes becuase I'm always here to provide the better alternative--music improvement.  But on why your music probably sucks...

1.  You listen to it because it's in a certain genre.  This reason is irritating; even being a fan of metal, I am nevertheless shocked at the amount of metalheads who will listen to anything that labels itself as alternative or metal.  Remember: just because it looks good doesn't mean it is good.

2.  You listen to pop punk.  Back in the day, punk meant something, something like anarchy and rebellion.  Now it means hot topic and complaining about your life as a junior high kid.  The Clash is punk, NOT Green Day, Good Charlotte, Yellowcard, My Chemical Romance, and certainly not Simple Plan.  Punk wasn't even that good of a genre to begin with, but the populace had to go and make it crappy.

3.  You listen to it because it's in TRL's Top Ten.  I think this is self-explanatory.

4.  You listen to it because it's indie.  I also think this is self-explanatory, but, then again, a lot of people are retarded.  Indie music, as touted by those bitches on Pitchfork.com or elsewhere, has problematic tendencies.  First, as seeming nonconformity to the auto-tuner pop "singers", indie music has the incorrigible fetish for lauding terrible vocalists.  Don't excuse it: you know they're trying but can't.  They're bad.  Second, if I wanted to hear music produced by eight-graders, I'd tell my little sister to make a band in a garage and save fourteen dollars on the compact disc members of the "elite" think is so amazing and innovative.

5.  You listen to it because it's a classic.  Listen, I know a greater portion of the world thinks the Beatles are good, but the world also thinks abortion is not murder.  (And we all know better than that, do we not?)  In all seriousness, though, older artists did make some very innovative original music, but a ton of it is very overrated as well.  In other words, you got to have balance.  Plus, production value has skyrocketed since the sixties, so chances are newer music on compact discs will usually sound better overall.

6.  You listen to modern country.  Bluegrass was beautiful type of music, but then came shit, and it covered all of Nashville.  Enough said...

7.  You listen to most Christian music.  When the lake's smaller, the chances of getting a better fish is equally smaller.  Same with music.  I've never been entirely sure where the majority of Christian music is going.  Lately, it's been creating (or "writing") as many three-chord, "next big thing" worship songs.  Come on, seriously, for God's sake, branch out a little!  I'm sure people can be a little more creative than they've been.  DC Talk had some good songs when they weren't covering someone else's (and same with Audio Adrenaline).

8.  You listen to "whatever's on the radio".  Enough said...

9.  You listen to bad pop.  There is good pop, if you look for it.  Michael Jackson's Thriller (not referring in any way to his deviant behavior) was a very good album.  Justin Timberlake's Justified is also a good album.  So good pop exists.  Ashlee Simpson doesn't count.  Lindsay Lohan/Hillary Duff doesn't count, and someone please kill the Click Five and Black Eyed Peas.

10.  You worship the band.  No one band is the all-encompassing peak of perfection, and chances are yours is not even close.  So stop the groupie fellatio.

11.  You listen to bands that capitalize on wartime.  Now, I'm not one to be too judgmental, but come on, you're not adding anything new to the "We don't like Bush" table by releasing a "controversial" album.  I don't care for Bush much either, but the trend past the point of simple vexation.

I may add some more later...