I can't help feeling that's a bit harsh. It's hardly a myopic world view to point out that the intention of carry-on is in fact carry-on. Wanted on voyage! Especially on Qantas who supply a minimum of 23 kg checked luggage allowance with every flight.
I can understand that there may be some people who need to carry a heavy lap-top and a multitude of paper-work with them, but since this discussion opened I've been surreptitiously spying on my fellow passengers and I've yet to see anyone who trundles two substantial bags into the lounge, availing themselves of the luggage they are travelling with. In some instances, I've been sharing flights and my conclusion is that those passengers with substantial carry-on are travelling HLO, simply to avoid checking bags in. Nice for them, but a bit rough on others who check luggage and then struggle to find room in the over head lockers. Surely the philosophy behind HLO is travelling ultra light, not compressing your normal luggage into a couple of solid wheeled bags that just pass for carry-on?
Perhaps instead of weighing luggage, Qantas should put corrugated flooring everywhere so everyone had to actually carry their carry-on. Bet that'd sort the problem.