Slashdot’s own code was open-sourced for other websites to build on top of. When HN was founded, it could have even used Slashdot’s own system of moderation directly. However, HN is part of Y Combinator, and the latter undoubtedly wants to protect its brand. Discussion on such corporate-owned websites naturally always entails more severe moderation than on hobbyist communities or ones run by a small business.

I'd prefer a vote or post scheme, maybe at the thread level. I like that at least you can't downvote people who respond to you.