In defense of CVS (which I personally wouldn't use anymore today), there's still a point to be made for being to able operate your VCS with only a handful of (mostly) unambiguous commands and having all of those exhaustively explained in a single man-page that doesn't fill a book-shelf.

Especially git has been doing a rather poor job at insulating the user from the immense complexity that the added flexibility incurs.

This is one area where our fancy new DVCS still have to learn from their ancestors.