I up voted you because I think it's a shame that people down vote for having a strange point of view. I'm assuming you aren't trolling :-) Having said that, I completely disagree ;-)

I've used RCS, CVS, Source Safe, Perforce, bzr, subversion and git professionally as a programmer (and that's not including home grown VCS systems that nobody has heard of). I like git, but it's hardly going to be the ultimate VCS ever in the history of the universe.

I remember using RCS and switching to CVS. You have no idea how happy I was! It was like night and day. When I eventually started using distributed VCS systems I had that same feeling.

We need a variety of systems where people are pushing the boundaries in order to get to the next level. I don't think Mercurial is the next level, but there are some really good ideas in it. Sticking to a single implementation will hold our whole industry back.

To be fair, learning a new VCS takes as much getting used to as changing the colour of your sneakers compared to all the other stuff you have to learn in your career. If you hold on too much to a small little island of technology, you could find that the rest of the world passes you by pretty quickly (Speaking as a fairly old guy, a lot of my former colleagues are in that predicament right now -- it's not fun).