As true as that all may be, there is still no reason to be a dick to people who make "Show HN" posts. One can be critical without being offensive, insulting, rude or belligerent. But too many people seem to think that being obnoxious is The Right Thing To Do for some mysterious reason.

Constructive criticism, preferably actionable feedback, is one thing. Saying "you suck" is quite another.

I'm reminded of an old saying, which goes something like (paraphrasing here): "Everyone has their own battles to fight. Be kind to everyone, for you know not what battle they are fighting".

Besides, it doesn't cost any extra to be polite and reasonable, versus being inflammatory and attacking.