Instructor User Set-Up Event Category Box as an Exception vs Eligible

It would be nice if the Event Category box in the Instructor Set-Up was either a Select All option or better that it was used for Exceptions they couldn't do vs what they can (so if that box is empty they are able to teach all classes). We have 30+ Instructors that we have to "catch up" and add our many Categories to so that they don't show a Conflict when assigning in a Event Set-Up unless they are already scheduled for something. Also, if we add a Category we have to go into each Instructor again to add it to their profile.