Narcissism of small differences
it is precisely communities with adjoining territories and close relationships that engage in constant feuds and mutual ridicule because of hypersensitivity to details of differentiation
For example, because Java and C# are so similar, their users are more likely to feud, not less.
At a smaller scale: tabs and spaces make no difference to a running program, so proponents of each are the most likely to feud.
Same for brace positioning.
People pour effort into these things because they are a way of asserting their identity (either group identity or individual identity).
(Research shows me that Raganwald spotted this in 2008 (discussion))
Joke from Emo Phillips:
Once I saw this guy on a bridge about to jump. I said, "Don't do it!"
He said, "Nobody loves me."
I said, "God loves you. Do you believe in God?"
He said, "Yes."
I said, "Are you a Christian or a Jew?"
He said, "A Christian."
I said, "Me, too! Protestant or Catholic?"
He said, "Protestant."
I said, "Me, too! What franchise?"
He said, "Baptist."
I said, "Me, too! Northern Baptist or Southern Baptist?"
He said, "Northern Baptist."
I said, "Me, too! Northern Conservative Baptist or Northern Liberal Baptist?"
He said, "Northern Conservative Baptist."
I said, "Me, too! Northern Conservative Baptist Great Lakes Region, or Northern Conservative Baptist Eastern Region?"
He said, "Northern Conservative Baptist Great Lakes Region."
I said, "Me, too! Northern Conservative Baptist Great Lakes Region Council of 1879, or Northern Conservative Baptist Great Lakes Region Council of 1912?"
He said, "Northern Conservative Baptist Great Lakes Region Council of 1912.
I said, "Die, heretic!" And I pushed him over.