[lmm]

I don't want anything my computer ever does to be irrevocable. If you want to always commit one at a time and never change them, that's fine - you can just never rewrite your history. But for many people rewriting history is useful, because it's easier to see what the correct commit boundaries in your change are after you've done the whole thing. That git allows these people to do that can't possibly be a disadvantage to using git.