The rapid pace of Chinese urbanisation and economic advance from such a low base has meant China's development has been necessarily highly speculative. There have been huge wins on projects that in the west would look absurd, as well as huge losses.
What you also have to remember is that the state has a huge interest to keep construction happening as its one of the biggest employing industries.
However development is trending now overall towards a more mature western approach. Big developers are more experienced. Unmet demand it not as massive as before. And wages are rising. The ridiculous projects are reducing in pace and being more carefully organised.
A lot of the speculation will have to fall off. A good old fashioned property bust would do wonders to correct all the distortions in the market, but the central government keeps doubling down on more.
That's a nation with a very big unused hammer adventuring around the world looking for a nail.
China will eventually move to a high skilled labor force and these problems will go away. But that is not today.
Speculating on property is a horrible way to go about development. Building a new district in a second or third tier that is then speculatively bought out by rich city investors with the idea that there are lot of millionaire farmers who will relocate there later is just plain idiotic.