Why does this seem to happen in Sydney, in particular?

Say this just now:

Almost 1,000 recently completed apartments in Sydney’s north are at risk of collapsing due to “serious damage” to concrete in the basements caused by defective workmanship, according to the New South Wales building watchdog.

The developer Greenland has been issued with urgent rectification orders over the four apartment buildings at the Lachlan’s Line development at 23 Halifax Street in Macquarie Park.

The Building Commission NSW found there was “serious damage and spalling of the concrete slab at the joint locations in basements and the ground floor caused by defective workmanship” after inspections last year.

“This is a defect in a building product or building element that causes or is likely to cause the basement slab to fail, namely, to fracture and collapse, leading to the destruction of the building or any part, or the threat of collapse of the building or any part,” the rectification order said.

This is another example over the last few years of relatively new high rise apartment blocks in Sydney being found to have structural issues making them dangerous.  It would seem, from the list noted in this article in 2019, to be the fourth block that it has happened to.

What puzzles me is why these disasters seem particularly centred on Sydney constructions.

There was an ABC (perhaps Four Corners) show about the high rise residential building industry a year or two ago, in which they seemed to indicate that Queensland and other states had a more rigorous independent inspection regime during construction than NSW.  But surely these faults are related to engineers and certifiers who are engaged by the builder to check the work, too?   

I mean, I don't really understand how they can risk their professional reputation over certifying shoddy work that will come to light in the near future...