Gaaaaggggh. I don't know what it is about I/T that seems to bring out the "One True Wayism" in the people who do it for a living. Maybe the professions w/in I/T sort of select for that. Dunno. And really don't care. Except, naturally, when I have to break up a dog-fight in my metaphorical backyard...or actually am one of the dogs in that fight.
The bottom line is that if you're asking people to abandon current processes systems, they have absolutely no inherent reason whatsoever to believe that making your way their way will be worth the switching costs. There's a prophet on every street-corner for this language or that methodology or the other platform. They can't all be right all the time. Which all tends to breed a more than robust skepticism in anyone who's been in the trade for more than a few years. And when the prophet in question is already known to be prone to One True Wayism, making converts will be that much more difficult.
Kathy Sierra sums it up better and more pithily than I could when she talks about focusing on "making your users more awesome." And I think that's precisely the focus that anyone selling their peers on The One True Way should take. Don't tell me that the old way sucks. For all I know, that very well might be true. But don't tell me that anyway. Don't even tell me how awesome the new way is. My defenses against hard-sell hype make Cold War bomb-bunkers look like a cardboard boxes. Tell me how the new way's guaranteed to make me awesome. Scratch that. Awesomer. ;-)
Because if you can explain how the new way will make my life easier, that means you've actually taken the time to understand the old way. I don't think it's possible to overstate the breakthrough that represents. It's analogous ministering in a foreign country and being able to converse in the native language. You more than probably won't have the nuances, slang, etc., and you might even make a few embarassing gaffes. But you will no longer be just another God-botherer, brandishing a thick book and gibbering. Until then, it doesn't matter how many wells you can dig or schools you can build or people you can innoculate. Or whatever. You might as well stay at home and talk to yourself and save yourself the plane fare.
It's probably stretching the metaphor a tad to talk of dropping the "preacher" mindset in favor of a more "missionary" outlook. But I think that the difference is significant. Because, in the end, making your peers (more) awesome means that you hang with awesome(r) people and do awesome things more awesomely. And, seriously, how awesome is that?