Paraphrasing both Joel S and Marc G : Do you do everything my way, just 'cos I ( ... think I know better than a guy that ... ) runs a two-bit software company in New York?
Of course I sodding don't: my company writes for it's conditions and requirements, and not yours.
If I choose to use SVN or GIT or even PVCS, what's it got to do with you?
If the personal dynamics in the team are slightly competitive rather than perfectly "A: let's do it your, way. B: No your way. A: no, insist - your way. ... ad nauseam", does that preclude producing decent software? (I'm C, "C: will you just get it done already!")
Software development isn't about one process or another, it's about meeting the sodding customer's requirements, so they can get on with THEIR business, and most of the time they couldn't give a flying duck what methodology you use, as long as the software does what it says on the tin, doesn't cost too much, and isn't a pain in the ass to use every other day!