commercial skyscrapers

[tom]

I've tried a number of strategies for a commercial skyscraper to be built. I've made a city with very limited commercial zones in order for the buildings to be forced to build big to satisfy demand, building some banks near eachother in debug mode to see if they would combine into a skyscraper, and placing a large number of commercial zones to hope for skyscrapers to spawn. Currently I'm on my third city with NO natural commercial skyscraper spawns, despite a large and flourishing upper class. Why are commercial skyscrapers so difficult for them to build naturally without using a debug mode? I've seen a number of other users struggling with the same problem.

[tom]

Attached are another two cities, please not that the commercial skyscrapers in these did not naturally spawn and were added in debug mode to add more diversity to my city.