I think what Australo is probably referring to is the CTA steps Australia wide that have been compromised for the benefit of a few GA aircraft to avoid paying airspace charges.
For every other minute of the day there is a high capacity jet flying a compromised descent profile burning excess fuel and pumping excess CO2 into the atmosphere.
The problem is getting worse as a result of newer aircraft types with lower descent (more efficient) profiles.
This problem rarely exists anywhere else in the world.