In addition to the procedural issues already addressed, let me point out that airspace systems are extremely complicated from types of users, given the mix of commercial, GA and military traffic, and that adopting a new common standard applicable to all of these users is extremely problematic. As an example, the adoption period for ADS-B in the USA was specified as 10 years (we're about halfway through), and there is still a huge amount of resistance from the GA community due to costs of adoption etc.
