The first few times I got down voted it hurt a bit, but it is a signal (in many cases) that something with my commenting was wrong, and as long as that is the case I prefer to have it pointed out.
Note that there are also people being helpful when you commit errors, or write articles.
I think the less inviting feeling can come from the higher regard for content. In some atheism forums where I post we have super nice theists posting, and getting respected just for being honest and decent people. Which is fine, but they do not get any flack for the content they write. On LW you don't get additional karma points for being a nice person.