It is remarkable how different the St Lawrence project is compared to what Metrolinx thinks is good development. If you want to build a good mixed-use, you cannot build to maximum density and have a liveable environment. You have to have mixed-density and mixed heights. It's like Metrolinx thinks the only good development is a max development. That's not city-building, that's city-destroying.Towers cost-effective in Toronto given the cost of land. Shade isn't a new invention. Towers have been around for more than a century and shade hasn't been a big issue until some people decided that their front lawn deserves sunlight more than people deserve housing.
Building on top of stations and on construction lands helps subsidize the construction of the infrastructure. It also provides a new revenue stream for the agency/city building them.
If they can really justify the amount of commercial they want, then maybe build taller in individual towers, and break up the wall effect. And have smaller buildings also. Otherwise, it will be cold and barren and windy. There are other factors other than money that need to be considered.