But civil access to military infrastructure comes at a price - either increased risk at times or significant inconvenience.
Hang on civil operators pay money to fly in this airspace. If the military want their own systems they can pay for it out of their own budget and have the benefit of Military only zones. The RAAF gain from a cost reduction in running dual airports yet really don't provide a great ATC service, mainly due to their system of 'perpetual training'.