git's CLI design is byzantine and inconsistent, with terms that are both overloaded and underloaded (many commands do multiple, unrelated things while at the same time many common tasks do not have commands). It's very easy for newcomers to place their local repo into a limbo or failure state that they can't get out of without consulting a git guru. git's error messages and man pages are written for its developers, not for its users. git's overall CLI structure maps poorly onto its underpinnings, half-hiding parts and not explaining the rest. Pushing and pulling have really bizarre default behavior that easily confuse those who have not carefully studied how they work.

git is extremely powerful and is, buried underneath its abysmal UI, a thoughtful and elegant work of engineering. However, as a product it's incredibly difficult to explain to other people. Until you've invested a thoroughly unnecessary amount of time learning its gotchas, quirks, and vagaries it is a monumental pain in the ass to use.

(Don't get me wrong, I use git all the time and appreciate its power. I just wish Linus has asked someone else to design the CLI.)