We need a consumer mode that can be turned off only with a password. The purpose of the consumer mode is to have it on for users that will only be consuming content set up by a more advanced user.
When switched to consumer mode, Kodi cannot scan for changes, remove from library, delete files, rename, edit titles, or change settings.
Master lock does not provide this kind of limitation but it is more blunt. And profiles is a lot of work for just having a consumer mode.