Probably true. But at least in the open source community, it's pulled even with CVS and svn and is at least an order of magnitude higher than that of hg (or any of the other also-rans). Obviously "someone" important is going to use any product (see the irate comments for some great examples).

And there are very high costs to heterogeneity in this world. Using a weird SCM means that every new contributor needs to learn a new tool and new workflow, and that hurts. Using the one that "everyone" knows is a big advantage to projects.

And git is good. Not "the best" perhaps; and undeniably ugly in places. But it's more than good enough. And the existence of a community like github make it, frankly, better for new users than other options.