I was wondering what in particular is the downside of "losing history" in a development process. One famous example is of course git rebase -i / git merge --squash, but also what is described here: http://fourkitchens.com/blog/2009/04/20/alternatives-rebasing-bazaar under "I want to clean up my commit history prior to submitting my changes to the mainline." I can see that exporting patches and applying them to another branch would lose the "history" of the branch, but why would that branch and its commit history be useful after it has been merged? Can someone elaborate on why such techniques are considered "dirty"? Why does it matter in which order changes were originally committed in the first place as long as they can be applied to the main branch?