That's a good question. It's something to do with the human phychology. I've noticed that too. To quote an episode from Quincey M.E. : "You spend your whole life helping people, then you screw up once, and they never let it down."
Something similar here. People only notice mistakes.

Now, all my levels suck, (except the one for the CE Project,) and you know why? Because I make them for fun. Who gives a donkey's (-) about it? They say it sucks, but if it's fun and you like it, then who cares?

So anyways, just don't give up.