During the 'great git migration' of 2010, a lot of folks saw no need to move from CVS for Drupal, or CVS/SVN for their internal operations needs.
If you have -ever- had a merge conflict or file lockout and the migraine that followed, you should switch to a DVCS as soon as possible. Once you extol the virtues of using git, everyone will fall in line.
If you're working with Drupal you should already be a git ninja. If not, why aren't you using git yet?