You will find most headmasters feel the same way. The issue is that this fella turned up with huge wraps on him with the TKS magisterium thinking he would fall into line like all good Kings men. Then came the buckets of money. Previous to this, clubs would park players in GPS schools for a couple of years (pay they fees, boy would play for the school only) and in return the player would sign an agreement that he would play for the club for at least two years after year 12. Newington benefited from this system not long ago. The boys though did play for the school and the clubs never pressured them to play Sunday league.
Now we have a situation were a school allowed their player to play Sunday league. It seems Souths now want him to play exclusively with them and forgo school commitments. In future I am sure ALL GPS school heads will think twice before "investing" in talent that has the tinge of league.