I'm having trouble with the "if you need more housing, rewarding development is what you need to do." Part

From my limited understanding the purpose of a developer is to do speculative research to determine what building ideas they can make a profit off. They pay the builders and then find a buyer for the finished product.

So I can see how removing the gst can help motivate the building of apartments. but is that really the best strategy? It seems like a gamble to me. If it's still more profitable to build over priced condos they'd stick to that. Having affordable apartments near by those condos may lower the demand for expensive condos. So it may not be in the best intrest of developers to make them, let alone make them last.

We'd need somthing a little more systemic. Somthing not dependent on doing the profitable, thing but doing what is nessary to ensure there is quality affordable housing.