Some are just blunt and say "the code you wrote is stupid!" Others are even worse and say "you were stupid!" What does that gain us?

For me that's the dividing line for what I will consider acceptable behaviour. I can take (if not enjoy) the former. The latter I get cross about. Online and offline.

I also think that there is an easy line to draw between blunt and abusive.

If how they code bugs you, why is so difficult to take a few extra seconds to be nice about it?

Time is an issue. It can sometimes take more than a few seconds to rephrase something in a less confrontational manner. It can sometimes take several minutes, sometimes longer. For those with busy lives the choice is to be somewhat curt, or not provide input. Personally I prefer that somebody be blunt with me than not get the input.

(People may find this Wiki entry on Brutal Sarcasm of tangental interest.)

Actually, I feel somewhat two-faced about writing this since I do try to take the time to be non-confrontational and don't answer if I don't have that time (not that I always succeed) .

Unfortunatly, I do it for purely selfish reasons!

I've found that some people judge my personal approach to work by what I write online so I take the extra time to be pleasant so people will hire me.

I'm far nastier in real life than I am online :-)