Some settings can be made by non-administrator users by simply going into Settings. Others require Group Policy editing. For example, disabling the previewing when hovering over an icon on the taskbar.
In corporate situations, requiring edits to Group Policy or the Registry typically puts it out of reach of most users. IT has more than enough to do than to attend to these pesky little user customizations.
Some settings seem so innocuous as to not warrant their place in the Registry or Group Policy. What factors cause them to be put in the Registry or Group Policy?