At present we don’t support such a feature. (But you could export your account in Settings, remove the ratings column and re-import to a new account.)
An error occurred while saving the commentNoruberuto commented
the possibility to reset all star ratings with one click /tap would be nice.
plus, there seems to be some confusion with the display of full/half star ratings. i switched to full star ratings then back to half star ratings again, but there are still only five rating bars visible in my profile.