The NIMBYs will stop it, if Labor doesn't. Noise and "perceived noise" is the killer - people see something in the sky, assume it is noisy, and get irritated by it, the complaint ends up on the Minister's table, and with the next election only 6 months away, he will stop the lot.
If Sydney can't get one CBD heliport, it certainly won't get a bunch of suburban hubs ("Huburban"?)