One problem with git is that it assumes you have some sort of "diff" utility for before and after snapshots. For some types of things, that's not feasible - you can't easily diff two images and work out what filter was used. Sometimes you instead you want to create the diff, and generate the "after" snapshot. You could emulate this by stowing the information somewhere hidden and writing a fake "diff" that simply retrieves it - but saving the edit tree and reconstituting it is supposed to be git's job! You end up reimplementing bits of git, just to make git work.