That's understandable - from business point of view. I bet you would just use SVN instead of innovating with a new DVCS ~7 years ago. Safe choice is a safe choice.
Way back when I was looking at both (7 years ago maybe?), it seemed that mercurial's main selling point was functional equivalence to git with a "better" architecture and source language. This is the ultimate case study in the fact that neither of those things matter to users (even deeply technical users) unless they impact user experience (stability, performance, UI, etc).
[1]: http://en.wikipedia.org/wiki/Git_(software) [2]: http://en.wikipedia.org/wiki/Mercurial