True, but the desktop environments have files in the home directory that can cause issues. I recently had problems that could only be solved by creating a brand new user account due to the amount of times I rebased.
About the only time I would recommend rebasing is if you are rebasing from one image with KDE to a different image with KDE. I would not recommend going from an image with KDE to one with Gnome. I have done it and there are dragons on that path.