If only this were true. But it's not. It's my perspective that most programmers who adopt the usage of any version control tend to stick with the first one they learn. After that, they become loyal to that package, even if it dies off, they cling to the known quantity.
Well, I started with Rational ClearCase and use git now; in between I used (in no particular order) VSS, PVCS, CVSNT (+TortoiseCVS), and TFS. git is my preferred system of all of those, solving every shortcoming I personally experienced.
I doubt your assertion holds for programmers who moved from file-locking "checkout-and-edit" based systems to an "update-and-merge" paradigm. The latter is so much easier. By the end of my use of VSS, I was basically doing that anyway with one directory containing the source-controlled copy, and another directory containing the copy I actually worked on, and just merging back and forth as necessary.