Several of the people I worked with at Amazon were skeptical of git, at least initially. Some people prefer tools they already know, prefer the routine and habit over learning a new tool. And I totally respect that by the way, git's UX is superior in mainly aesthetic ways, in terms of tactical productivity it's more of a wash. I still think git has the edge, but there is nothing to say a seasoned developer who's used perforce for years isn't being exceptionally productive with it.

Nearly everybody I talked to about it eventually came around to prefer git though. Once you've been forced to swallow the bitter pill of learning something new and changing your workflow, I think the advantages begin to shine through.

On the other hand, maybe I'm just biased because I was proficient in git years before I was ever exposed to perforce. So maybe it was myself who was balking at learning something new, and that's why I was so relieved when my team switched to git. But I do genuinely believe that git has a superior UX.