Comes down to greed and speculation. The concept for the mall has worked elsewhere, and I'm not entirely sold that a big reason for the failure is the location (they were saying the same about CrossIron). The issue here is how they were sold. Instead of invoking a requirement that all sold spaces be occuplied by a certain date or turned back over... they had nothing. Pretty much all the spaces sold to speculators, looking at them as investments and saw $$$ thinking they could then lease them to these small store owners. Except then the lease rates are stupid high, and just are not feasible, even approaching rates in existing malls. In low margin stores that were being marketed, it's just not an option. This should have been restricted so that costs were kept low and store owners actually owned the space.
Developer must be laughing. He's been paid by all the investors and his end of the deal is done now that the building is complete. Lots of people got conned.
edit: Here's a good article on the problem
https://calgaryherald.com/business/l...remains-upbeat