[sisk]

Regarding losing data: it's as simple as diving into the reflog. In order to remove something from your history, you must do so very explicitly by walking your commit history, editing each one. There is an automated workflow to accomplish that (`filter-branch`) but it's definitely not a command anyone I know has committed to memory.

Accidental mutations can be undone either by `--abort`ing (if the command supports it) or by checking out an earlier revision from the reflog.

The GC in git is pretty conservative and, while it can be triggered manually, still makes you jump through some hoops to actually get rid of something. Steve Klabnik wrote about it[1] a little while back.

In certain cases, you don't have access to the reflog because a change wasn't made locally. Perhaps someone screwed up a remote you pull from and it destroyed your history. You can, even still, find, view, and re-associate orphaned objects. Yeah, it's not terribly intuitive and, again, not a workflow anyone has probably committed to memory, but the fact that you can recover from a disaster of that magnitude is pretty amazing.

git provides we developers with a set of tools—powerful tools—and that comes with a level of responsibility. I'd rather have the ability to responsibly clean my history than the alternative.

[1] - http://words.steveklabnik.com/git-history-modification-and-l...