You'd think that if you wrote something really great, you'd get praised. And if you wrote something really dumb, you'd get trashed.
But that's not the way it works.
Instead, if you write something really great then everyone tells you how dumb you are. And if you write something really bad, you just get ignored. Ask any blogger and they'll tell you its true. But why is this?
People naturally respond to what they read. If someone loves what you write, the natural response is to forward it to friends or post it on Digg. But what if someone hates your blog? They can't unforward it, nor can they delete it from the collective memory.
So they trash you. Because really, it's all they can do.
There are times when the blogosphere seems terribly uncivilized. Recent events like the Kathy Sierra death threats make this all the more salient. But not everyone hates Kathy. In fact, most of her readers love her. They express their love by reading her posts in the first place. But this support is largely invisible, so sometimes all that's left to see is the hate.