For people who don't see any cost to closed borders (all family and friends are in WA, no need to travel for work, etc) then life being 'normal' is seen as a preferred alternative to masks, restrictions, toilet paper shortages and a small but real risk of grandma and grandpa dying.
The 'costs' of border closures - economic, mental health, otherwise - are too far outside of most peoples' direct sphere of observation or influence to make them act.
The
terrible case of a girl dying in the childrens' hospital waiting room shone some light on this (I am surprised Roger Cook managed to keep his job).
Ambulance ramping hits the front page from time to time as well - but again, because the numbers of people impacted are low - and it's outside of most peoples' observation and influence - it doesn't reach a tipping point of causing a public outcry.
It's much easier to throw stones.