Most people prefer what they already know (learning any new system or process is always frustrating because you are attempting to map concept rather than learn concepts - square peg, round hole).

I prefer (and use) git myself, but it took awhile (and much of my developer/friend network to go first) for me to commit to the switch from subversion...my main issue was that subversion worked well enough for what I needed/wanted at the time. I didn't really switch until it became harder to work with others because of my subversion use and easier to work with others if/when I adopted git.