I'm not against levelling the playing field economically
Well you probably should be.
HECS would have an additional outcome to those you outline - the cost of flying training would go UP substantially...as has happened to every UNI course you can think of from Arithmetic to Zoology.
There are few enough barriers to entry in this industry as it is - the last thing we need is 'free' Govt money flooding the industry with minimally talented, dreamers. And People who come on here and whine 'I have dreamed of being a pilot since forever but, gee, the starting pay aint great and I am wondering whether I'd be better off driving dump trucks in the Kimberly' are just that - dreamers.
You can't whine about low pay on the one hand - and usually from a position of ignorance as per the link provided by MA - and then bleat that pilot training should HECS subsidised on the other.
The ONLY people we want behind the controls are people who couldn't even BEGIN to imagine doing anything else.
Those of lesser dedication merely block up the system. Make it easy for the weaklings and you just raise the costs for the truly dedicated and talented.