Git has an absolutely atrocious interface, at every level.

The power it gives you once you've mastered it is probably worth it, but I'm not sure of that, and I think a much better UI that still retains a lot of the power (and adds more horsepower, even) is very possible.

I consider my worst pieces of software to be the ones where I cannot, for the life of me, understand even a tiny amount of why things were designed that way, or why things fail, or why I continue to subject myself to such torture. For the technologies above, I run into many issues with them, but I frequently feel that is on me, not on the software. They have also solved many real problems as well as exacerbate some others.