I think the more-likely explanation is that many Melbournians were well and truly 'over it' a long time ago and there was widespread non-compliance with the 'tight restrictions'. But I have no hard evidence to support that.
No doubt.
But surely someone in the ivory tower could sense the attitudes of the people wandering around below.
Rather than fighting that with tougher restrictions, which only promotes further non-compliance, they could have let people be more free outdoors with probably a far less case load than they have now.