Who would pick the name subversion? The word means an attempt to overthrow authority. It's also a nice pun on its purpose (version, my dear lost reader, version!).
Who would pick the name git? The word has only pejorative meanings.
And then you get mercurial. The word has both marginally complimentary and often uncomplimentary meanings.
Which brings us to ClearCase. Commercial. Bloated. What a deceptive name!
The moral? If it's got a sly name, it's probably better for you.