It's probably a mix of both.
Local market is not as profitable as other places in North America, this is obvious, and has been heavily debated on this forum. It is one of the reasons why we see Toronto developers bail out time and time again. There's just not as much money for them to make here as there is in other places that they're more familiar with (mostly Southern Ontario, in general).
But the Chinese real estate bubble has definitely burst, capital is tighter in China and the government has been very controlling with external expenditures, especially in things like this, because they want to keep as much capital as possible inside of the country. This was probably even a bigger factor than the first one, but it does not make he fact that our market is not as profitable for developers as others in NA.