Sorry, but by declaring that "the industry and shipping that city planners envisioned when they began to fill in the harbour south of the rail yards never materialized", you are misrepresenting what actually happened. Queens Quay Terminal, the Power Plant, Redpath, the LCBO complex, and book-ending grain silos remain as testament to the buildings that were there. Many marine terminal warehouses have long since disappeared. Much of the industry moved east into the area today that we now call the Port Lands.
What is the indication that Harbour Square was built as a fortress to emphasize the area's industrial past? That's not my take at all on why it was built as you see it.
The parking garage, of course, is the big problem here. It's above ground instead of below because it's cheaper to build up than down, and far easier if you don't have to deal with the seepage issues presented by having the lake mere metres away.
Also, at the time there was no draw to the area other than as a spot to hop on the ferry to the Islands. People certainly did not stroll along Queens Quay, and it seems no one even assumed that might be a possibility in the future, as the public realm along that street wasn't given a second thought there.
You also speak as if there's a possibility that Harbour Square might be torn down in the foreseeable future. How could that happen?
42