Private Schools are going to do what they want to do, and will act in their own best interests, not the interests of rugby in general or SJRU in particular.
There is little alignment of "seasons" within the school association competitions let alone a willingness to realign their seasons to allow SJRU to offer viable alternatives that recognise the demands of school rugby in the older age groups.
Private School students are cocaine for SJRU and SJRU have become addicted to that cocaine. They make it easy to recruit numbers for teams, and bolster playing numbers, which in turn make for happy annual reports and census figures. Going cold turkey and having SJRU rely on players whose schools do not have rugby programmes would in the short term dramatically cut team numbers in rugby's "heartland" in the East and North.
The Village Clubs in the East and North would have to do what they do out West and in the South, and work their backsides off to recruit and retain kids from public schools, the catholic school system, and other codes. The likes of Eastwood, Penrith and Parramatta districts would start dominating Junior State Championships. The quality of play and players would be seen as being inferior to that of the Private School system. I'm not sure why this is a problem, but for some it is. Not dominating State Championships as they have traditionally done through their abundance of private school players seems to be a bitter pill that some administrators and districts do not want to swallow.
If player numbers and "quality" drop in Sydney, then the "centre" may be forced to do something about it. At the moment, ARU and NSWRU can sit back and bask in the reflected glory of the heavy lifting that the Private Schools are doing for them. This costs them little time or effort, but does very little to grow the game beyond the traditional enclaves. We are seeing that player numbers in the private school system are hardly going gang busters with some schools now having more diveball teams than rugby teams. The Private Schools don't care, they just want their kids to play a team sport for character development purposes.
To get player participant numbers up in SJRU without relying on the Private Schools is going to take some serious effort and money from ARU, NSW RU and SRU Clubs. The volunteer based Junior Village Clubs have little ability to do much on their lonesome. Problem is that there doesn't seem to be any no money, or will to commit those resources to assist the Junior Village Clubs to spread the gospel in the public and Catholic school systems.
With the prospect of having to report a fall in player participation numbers, the Administration seem happy to remain addicted to the Private School Player cocaine. Suddenly all the problems of the world go away, and "normal" service is resumed. With the volunteer Executive seeming only be interested in doing a couple of years "service" while their young'un is going through the system it's a case of "Steady as she goes Captain". Leave the journey into uncharted waters to the next watch.