We hackers are just dying to let others know how smart we are. It's what makes us tick.
So we come here (and other forums and blogs) because most of us have trouble finding peers who even understand what we're talking about. Add in a lack of writing style and the anonymity of the internet, and our puffing and strutting APPEARS to be nastiness.
Put us in a room together to discuss the same subjects and I'm sure it would be much more civil.
Honestly ask yourself. Whenever you heard someone else getting a compliment for being smart, (Alan made the Dean's list!), (Joe is a great chess player!), (Fred wrote the best program I ever saw!), don't you get JUST A LITTLE BIT JEALOUS. You almost want to scream out, "Hey! What about me? I'm smarter than that!" We hold back in person because we're polite. But we don't hold back here, because most of us understand. Sometimes I think that if you DON'T think like that, maybe you shouldn't be a hacker.
Reminds me of an old story that Rabbi Harold Kushner told about a young man trying to temper his competitiveness, so he joined an ashram in Japan. He wrote to his father, "Dad, this environment has helped me evolve to the point of enlightenment where I no longer have to compete with others to achieve my bliss. The meditation has done it. I'm one of the top 5 meditators here, and hopefully, by next year, I'll be Number One."
[UPDATE: I just read the comments about this pg essay on Reddit, and realize that it's different over there. They ARE nasty. What's happened to Reddit? Whatever it is, I sure hope it never happens here.]