I've had a similar discussion with my wife just last night. She's a landscape architect and deals a lot with people who's purpose in life is to save existing trees and plant new ones. She complained that they're so over the top in their actions that they're often doing more harm than good (to the cause). It's similar in other niches - animal rights activists do some nasty things to fur coat owners, etc.
I believe that these traits (a strong belief in something and overzealous approach) are most often inseparable. We can either have these people care a lot and spread the word by doing things the way we don't agree with or don't have anybody who gives a shit.
I don't agree with Stallman on many issues and I'm eternally grateful to him for what he's done. I don't agree with tree huggers because they make other people laugh at the whole thing. But I'm grateful, because without them nobody would care. Same with animal rights fighters, same with GitTip folks.
Thank you, Chad Whitacre, the World is a tiny bit better because of you.