To be fair, most people who find it complex do so because Git has a very crappy UI. You don't need to understand the internals to use Mercurial, and I would imagine that's true for most other DVCS's. In that sense, I sympathize with them.
I'm pretty sure half of the teams that find Git too complex wouldn't find Mercurial to be complex. But they haven't heard of Mercurial.
I'm the guy people at $work call to do git submodule reorganization, troubleshoot lfs or recover disasters. I'm certainly comfortable with git. It gets the job done. The same can be said of svn.
However my own projects always start with hg init. In addition to the UI being less insane it also feels consistent and nice to use.
At one point I was on a team using Darcs, which was another level of beautiful but clunky in many ways. It is why I'm rooting for the Pijul team. [1]
Same here. I use Git at work, but anything I control I use hg. The only factor making me more likely to use Git is Magit, and no good equivalent for hg in Emacs.
I'm pretty sure half of the teams that find Git too complex wouldn't find Mercurial to be complex. But they haven't heard of Mercurial.