Less cross pollination. I think of HN as a very specific subreddit, without the worry of having users from other subreddits 'brigading' as the cost to do so req

Less cross pollination. I think of HN as a very specific subreddit, without the worry of having users from other subreddits 'brigading' as the cost to do so requires registration. At reddit you can come across a post and easily make a pun, incorrect statement, or troll much easier.