They largely became unmaintained. I'd still prefer to use bzr over git, and I do with Launchpad.net for code hosting, but for any work, git has "won".
I do not understand why so many people feel it's imperative to use one SCM tool for all projects, since learning the basics is very simple for all of them (except maybe for git itself).
I get it why commercial hosting platforms standardize on one tool (everyone will ask for git, so why double the work?), so I suppose the desire not to run your own code hosting is the main driver.