As sibling comment notes, that's going away. Even when it was around (and in my mind is now replaced by sr.ht), the problem is that 90% of projects (not a real number, obviously) were using git hosted on github, so if I want to contribute, then I'm going to use git and almost have to have a github account. There were never a huge number of projects hosted on BB, and an even smaller slice of those used hg.
