I think most people on LessWrong are reluctant to downvote, and very few people do it thoughtlessly. That said, getting downvoted happens, and I think you are too concerned by it. Downvoting simply means “I would like fewer comments like this.” When you get several downvotes (three or more, I’d say), you should take this signal seriously; when it’s a single downvote, I’d really let it go.
I think most people on LessWrong are reluctant to downvote, and very few people do it thoughtlessly. That said, getting downvoted happens, and I think you are too concerned by it. Downvoting simply means “I would like fewer comments like this.” When you get several downvotes (three or more, I’d say), you should take this signal seriously; when it’s a single downvote, I’d really let it go.
You should also check out, if you haven’t yet, Eliezer’s explanation for encouraging people to downvote.