A big factor in the equation (particularly as it relates to California) is transferable units and limitations based on which are automatic feeder schools. Those aspiring to a HA, of course, tend to have a strong academic goals. It has become more and more difficult to get all JC units (or 4 yr schools for that matter) to transfer. It is helpful when there is a feeder pipeline from specific JC's into specific UC's or CSU's but then you are limited to just a few schools who may or may not have a recruiting need at that particular time for a player with your son's attributes.
While it seems only logical that any California JC classes would transfer to any CSU, that is definitely not the case.