Command names are closer to SVN/CVS ones, which lower the learning curve for similar concepts.
The documentation really is at another level of didactic compare to git, and no, pro-git is not enough neither.
Changes are tracked automatically, no need to explicitly add the files you changed to a particular commit (Whether or not it is a good idea is another discussion).
Empty directories can be versioned, no need to create a .gitignore in it to fool the system (Same remark as above).
The syntax is part of it being easier. Also, though it's been a while since I tried using any official git documentation, bzr's website had handy tutorials, references, and cheatsheets available. Great layout, assumed no VCS experience.
That's not conceptually simpler, that is just easier to learn. Git's concepts actually are simple. You can explain the concepts and guts of git to developers with a whiteboard in a few minutes.
The standard CLI UI is admittedly a weak-point, but it does not appear to have slowed adoption...
I get what you're saying, but it depends on how you learn it. I tried learning both of them through their official tutorials and /their CLI commands/. With git's more confusing command set, I had a harder time learning.