I would guess the driving force for “ugly” architecture is cost. Straight unadorned walls are faster and cheaper than moldings, carvings and columns.
I have nothing against Canada, but I find this to an extreme there. I was in Montreal recently. Anything outside the city center is cheap box architecture, with a few cheesy “modern" adornments. Its soviet architecture softened slightly for a mass-marketing and commercial purpose. America has the same, but they are further down the soul-destroying path of post-modernism and phony collectivist- materialism than we are.