I think the question betrays the authors bias and assumes too much; by claiming that "almost every article comparing mercurial and git" and saying "it seems like Mercurial has a better command line UX", the author is obviously a fan of Mercurial; neither of those points seem to be true. While I can understand the sour grapes at seeing an "inferior" technology win, it's not that clear cut. I haven't used Mercurial eno…
I use Mercurial and Git every day, and I can tell you there's a marked difference between the usability of Mercurial and Git. Git would become totally unusable if it weren't for stackoverflow and google, while I can figure everything out just from Mercurial's short and sweet help manuals.