http://blog.ycombinator.com/new-hacker-news-guideline
"Critical thinking is good; shallow cynicism, on the other hand, adds nothing of value to the community. It is unpleasant to read and detracts from actual work. If you have something important but negative to say, that's fine, but say it in a respectful way."
https://news.ycombinator.com/newsguidelines.html
"Avoid gratuitous negativity." "Resist commenting about being downvoted. It never does any good, and it makes boring reading."