Its concepts easy to understand and git is very powerful, but the interface is horrible and a bitch to learn. Git does not need another tutorial, it needs an alternative porcelain.
Prevents? There's nothing like that. The only something about git that hampers comprehensive porcelain alternatives is the lack of orthogonality in git's plumbing.
People spent years bitching about CVS before a few Apache-related people got together and wrote Subversion. The long time it took didn't point to anything fundamental about CVS preventing anything.
