Git clones the entire remote repository to each developer's machine. So, if you accidentally committed something you shouldn't have two weeks ago, everyone will

Git clones the entire remote repository to each developer's machine. So, if you accidentally committed something you shouldn't have two weeks ago, everyone will now have a copy in their local repo. And you can't always just tell people to delete their local repos and start again, since they might have local branches they're working on, etc.