I think it's mostly about risk aversion. I've seen the exact same thing trying to push SVN over VSS. No one honestly thinks that VSS is the superior product, but once you have 5 plus years of history with it, it's what you know, and no matter what the reasons are, that is a risky proposition.
We're talking about people who would never shave a Yak because they'd wrangle 100 hairy Yaks than spend 20 minutes reading how the automatic Yak shearers work.
Well, yes, that's probably ultimately true in a lot of cases, but if you approach it constructively, you have a much greater chance of success than if you just assume laziness.
