Yes, economics dictates that the tower is the dominant form being built in downtown Toronto. But what is the form of the tower? Why aren't the new towers downtown being built as towers in the park, or towers in the parking lot? Why are they building out to the street now? Why is attention - however insufficient at times - being paid to podiums and ground-level retail?
Because thinking changes, amongst architects, amongst developers, amongst planners, and (perhaps least) amongst consumers.
There is a fundamental difference between this infill project and the project that originally cleared the site. The same economic pressures will yield very different developments, depending on what point in time you apply them at. Based on what I see, I think this is a good time.