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).