I know the logic seems odd.  

I wanted to have a global setting that would be the setting unless overridden by a particular workspace.

Not being familiar with this part of Geoserver I first tried to only have it in the settings.  However when added it to the UI it would fail because the GeoServerInfo didn't have the method.  So I added it to GeoServerInfo and it worked.  Then I noticed the verbose setting which, like my new setting, was deprecated in GeoServerInfo and declared in settings.  In the same way as my setting removing it from GeoServerInfo will make the admin UI fail.  I figure that when that can be removed my setting can also be removed (or maybe undeprecated).