[neilc]

I think another reason for this behavior is that programmers often define their identity in terms of their preferred tools (you're a "Perl programmer", not merely a "programmer"). That means that any perceived slight against a programmer's preferred tool must be aggressively defended -- hence the abundance of religious arguments about "$X is better than your favorite language."

[theBobMcCormick]

I think there's a very similar dynamic at work in politics, where people self-identify as a particular party or supporter of a particular ideology, an then take any criticism, however mild" of that party or ideology as a personal attack upon their very identity.

[kalid]

Yes, I think this unfortunate tribal protection trait is built into human nature. In the past it may have helped, but we end up forming (and violently 'defending') tribes around random things. It seems religion, sports, politics, etc. play on this instinct.

[michaelfairley]

pg has an essay about this very idea: http://www.paulgraham.com/identity.html

[theBobMcCormick]

Ah, I should have realized. PG is da man.

[mpk]

Some programmers are like that and they are horribly annoying to work with. Zealots always are, regardless of the environment you're working in. You can't have a civilized discussion with them so don't even try.