I think you’ll find that military pilots, who routinely operate in controlled airspace and at civilian airports across the world, are every bit as cognisant with civilian regulations as their civilian counterparts!
I think you are missing the point.
A PPL/IR can also legally operate in controlled airspace, and at civilian airports across the world, but will have no idea at all about (for example) performance regulations for public transport operations, all weather operations regulations, air law, etc because a PPL has not studied all the theoretical material required for issue of a CPL.
As UK military pilots also do not study the same theory as civil pilots how could the MOD argue to EASA that the qualifications conform to the same standards?