The NBAA is a very effective advocate for business aviation in the US. I note that in one of their surveys the top 100 (IIRC) of the Fortune 500 companies used business aircraft as part of their operations and counted them as essential for their operations.
However, the US is a far more dispersed nation that Australia, especially where its business' are located, which prompts private aircraft use. In Australia the majority of business' are located in the capital or regional cities which are supported by RPT.
I also note that the majority of corporate aircraft in Australia tend to be used as the private runarounds for the CEO. In the US it is not uncommon for sales teams, engineers and other coal face employees to be using the corporate transport.
This is from an on-line article written by John Deakin following his move from airlines to corporate aviation, sadly now curtailed:
While stockholders may be distressed at the thought of high-level executives jetting around the world at their expense, what I've observed has not supported this attitude. On one trip all over Europe, sometimes two moves in a day, the sole two passengers worked hard during every flight. They would clean up on board, and hit the ground running, selling some sort of very large international buy-out. It would have been totally impossible to do any of that, using the airlines. One very impressive frequent customer works with an intensity that is frightening. Food is placed nearby, and if he eats, fine. If not, it quietly goes away. How much productive work do you suppose he'd get done on the airlines?
I think it demonstrates how corporate aviation should be used.