I've always defended MySpace due to what it does for independent musicians—anyone can post music and create a page for free, and so suddenly the whole question of legal/illegal downloads becomes mute: just go to their MySpace page, and listen to some songs there.
But since anyone can create a page, there are a whole lot of anyones out there who should probably be finding better ways to spend their time. Which is to say, I am sick of getting friend requests on MySpace from crappy bands.
See, if you dare to list bands you like on your profile, or are friends with bands you like, inevitably, wannabes from all over the world will try and lure you into being their MySpace friends. Now, I'm not against being turned on to new bands ... it's just the way some bands do it. I prefer the "send me a message and tell me a little about yourself" method. I probably still won't add you, but I appreciate the semi-personal effort.
But just flat-out asking to be my friend, when I've never heard about you? Then, being the good music critic that I am (ha!), I actually have to go to your page, listen to your music and then make a decision. This takes time. I don't even know you, and you're wasting my time. I end up listening to a lot of appalingly bad music. The worst is when the music is just mediocre. It's like, you went to all this effort, and your music's just OK? C'mon. There are too many damn bands out there for you just be kind-of-good.
Now, I should say that I have actually found some pretty interesting artists through this will-you-be-my-friend? technique, but then I get friend requests from bands like this, and it just brings into focus the high-school like desperation that MySpace creates.
No one needs 5,000 friends. Really, you don't.