$WORK started using it (after looking at SVN and Hg as well). I liked it, so I started using it for my personal projects as well. Then Perl switched.

I don't claim Git is better than SVN or Hg (as I have never tried them). But $WORK uses Git; it works well at $WORK; it does what I want for my personal projects, so I have no reason to learn something else as well.

So, I guess my reason is "Since I already know Git, and Git does what I need". Oh, and I probably don't use more than 10% of the features Git has, so whether Git or Hg (or SVN) has more features isn't interesting for me anyway. If I had to learn SVN or Hg for $WORK instead of Git, I'd probably be using it now.