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.
