I wondered about this myself for some time now, so I set up a test account for myself using the "User is allowed to change password and settings option".
The only settings allowed to be changed when this option is selected are settings that only affect that user. They are:
Personal: Default language and theme, and the choices of what to display on the browse and Playlist windows.
Also:
Show what others are playing Show chat messages
Let others see what I am playing Party mode
Notify me about new versions
Notify me about new beta versions
Register what I'm playing at Last.fm
All these settings only affect that user, therefore each user can select their own theme and display setting. There really isn't any need for Sindre to change anything other than perhaps to reword the option at the checkbox from "User is allowed to change settings and password" to "User is allowed to change PERSONAL settings and password." maybe he should also add one of those ? help boxes to better explain that selecting this option only affects display options for the selected user.
Damn incredible what a fellow can learn through testing, isn't it.
