Steven: I don't like when people downvote my lesswrong comments without commenting, because then I never get to learn what's wrong with them

Agree, I hate that too. When that happens to me I just repeat it in different places until someone finally explains how I am wrong and just accept the karma hit. I have no idea what people are thinking who just downvote. If I knew that I was wrong, or how I was wrong, I wouldn't have written the comment/post after all.