What is the purpose of this feature?
to make new pages for new people
If you need to preserve the default settings, you can save the Default profile right after the installation and re-save it under a different names when you need the default settings.
you're right, but what if you forgot to do such save - like me :

- or some of your friends mess-up it, so I see a reset button or an option to make new clean profile will make the profiles'e settings kind of better. However, I see also it's not that necessary.