My argument goes like this:  Every developer has a fixed number of "brain
cycles" to use on any given day.  Some of this brain-energy must be
expended for overhead, such as finding ones way to the coffee machine, or
operating the version-control system (VCS).  The fewer brain-cycles one has
to spend on the overhead functions, the more there are available for us in
writing code.

The goal of Fossil is to require fewer brain-cycles.  Fossil isn't
perfect.  I'm sure there are things that can be done so that it requires
less effort.  But I believe it is better than monotone, bzr, or hg, and way
better than git.

Of all of the VCSes out there today, surely Git requires more daily
brain-cycles than any other.  I'm not talking about just the learning-curve
here.  Git requires more thought and attention even after you know it
well.  And that extra thought and attention that you devote toward
operating Git could be better spent working on your project.