This decision clearly results from the number of runway 'incidents' out in Goodyear over the last 6 months.
Particularly - the really really bad runway incursion that left an a/c written off back in the Summer.
I'm not sure the decision rests entirely with the flying school in question but I suspect the FAA might have put a certain amount of insistence upon the school due to the increased regularity of these incidents.
Obviously it's a disadvantage to any student going out there to train.
I guess the only option would be to try and sneak in some touch n goes at Mobile, Gila Bend, Buckeye - and if you're likely to get caught go to one of the controlled airfields and do it, Chandler / Williams Gateway / Deer Valley?
I believe the flying school has undergone an element of restructure and the guys who are now heading up the operation are pretty decent guys - albeit strict and very much by-the-book but I expect the FAA have had a quiet word and this is the result.....