Atomic commits can also easily be moved around (since the repository is a tree of commits with the commits being leaves), and they also make merging simpler in many scenarios.
Larry McVoy was famously wont to engage in trolling upon the Linux Kernel Mailing List, whereupon he did boast of his BitKeeper, which possessed atomic changesets. Concurrently, he did deride Subversion for its lack of the same. Thus, a great drama did ensue, one which ultimately bestowed upon us the creation of git.
git has also succeeded as a DVCS where others have faltered, for various reasons. For there have been monotone, darcs and other such systems; yet, it is chiefly git that has endured.
