Git has a horrendous user interface design,only mitigated by systems like github which manage to abstract much of the inconsistent logic of the interface from the user. Torvalds may well be an excellent coder but I wonder how this lack of "taste" for a better word has effected the linux project itself.
One guy writing the internals of git: conceptual integrity. One thousand guys writing the so-called "porcelain" of git: conceptual dyslexiphrenia. Open source may be great for fixing bugs. It's apparently not so great for designing interfaces.
I'm trying to become more comfortable with git, but I'm afraid I found this site a waste of time. It's not the concepts that make git hard to learn - it's memorising all those bloody commands.
Apparently this is important: References Make Commits Reachable.
[EDIT] Actually this is a great resource. Very clear thinking and explanations.
It's not hard...
That's subjective. Many programmers would probably have a difficult time even understanding what git is, much less how to use it. Once you get over that hump, sure, the basics are fine, make repo, add files, branch, push. Anything beyond that suddenly becomes arcane magic.