Random downvotes for perfectly civil comments are by no means due to an "elitist negative voting policy of this forum". I think this is a direct result of some idiots joining HN recently. I call them downvote-trolls, whose only purpose seems to be to elicit reactions such as yours. Please don't leave because of this.
Yeah I meant relatively new accounts. You do need 500 points to be able to downvote, but it's also become easier to get to that level by simply posting linkbait articles from any well-known blog.