I, too, believe Qantas has significantly improved the priority boarding benefit, so much so that it's now actually offered rather than just being a fluffy 'on paper only' benefit. That said, I would suggest people make an effort to discretely look over the shoulder of the person in front of them at the gate and see whether in fact that person is indeed entitled to the benefit. As I've posted several times before, I frequently use the priority lane with my AA Platinum/oneworld Sapphire membership which is not entitled to the benefit but have not once been politely told to move aside and go to the back of the line.
While it's all well and good to offer it and make the announcement and have the pretty signs, the process doesn't work if people use the priority line when they're not entitled to it and the gate agents simply let them through.