Really good points. I'd like to add that "iconic" is earned, not built - personally I wouldn't say the "Freedom Tower" is iconic per se at this point - the vast majority of people in the US, nevermind the world, wouldn't recognize a picture of it. The same is even somewhat true of the Burj Khalifa at this point. The Eiffel Tower is iconic - an entire trip to Europe is often (sadly) reduced to a picture or trinket of the Eiffel Tower. Big Ben is the same way. The Gateway Arch is the only midwestern structure outside Chicago that stands any chance of being "iconic", And Chicago's only real contenders are the Sears Tower (because it used to be the world's tallest) and John Hancock (because it's really distinctive).Iconic is a really high bat for anything to meet including a building. In my opinion for something to be iconic it has to be something that is burned into people brain that they will never forget. There aren't that many iconic buildings in the world. The Freedom Tower is iconic, the Statue of Liberty is iconic, Burj Khalifa is iconic, the Shanghai Tower is iconic, the Eiffel Tower is iconic, Big Ben is iconic. There are a few more but not many. There was never going to be an iconic building on this block. Hell I would argue that the Twin Cities don't have an iconic building, that's not a shot at DT MPLS or StP that's simply a result of having such a high bar to clear.
I think the city set the bar too high and instead of using iconic they should have used signature. The IDS is a signature building as is Wells Fargo and Capella. I would argue the Guthrie is also signature building. The Duval proposal is a signature, yes partly because of it's height. The Mortenson proposal isn't nor is the Doran. The UP proposal solid but I don't know if it's a signature building. That's why I think the Duval proposal is the one the city should choose.
I do think your post also focuses on height as a defining characteristic of "iconic" which seems a shame - many of the world's most iconic buildings aren't very tall. Without getting into ancient structures, the Sydney Opera House, the Guggenheim, the Grande Arche de la Défense (which admittedly *is* pretty tall), the US Capitol, the Houses of Parliament (including Big Ben), the Brandenburg Gate, the Arc de Triomphe are just a few examples of buildings that most people in the *world* recognize immediately but aren't tall. The only supertall building that likely belongs in that company is the Empire State Building, and possibly the World Trade Center towers while they stood; perhaps people outside the US generally recognize the Sears Tower, Chrysler Building, and John Hancock Tower, but I doubt it. Supertall monuments probably fare better: the Eiffel Tower and the Statue of Liberty are broadly recognized, and the CN Tower may be as well, though even there I wonder how well the world is aware of the Arch.
Anyway, if I were a betting man I'd guess that our structure most likely to be recognized outside the Twin Cities isn't very tall at all: the new Guthrie Theater. It was designed by a very famous architect and has a pretty inspiring design. Still not "iconic" by any means, but if Minneapolis were to end up on the map it seems more likely the Guthrie would be captured than any generic same-old tower. One steel-and-glass tube looks a lot like the next to the average non-architecturally-inclined person.
So I agree that "iconic" was too high a bar, but I'll go further to suggest that height isn't too likely to make something meet that bar, unless it's truly world-topping. I know people around here talk about Cleveland having a really tall building, but I couldn't pick it, or Cleveland's skyline, out of a lineup and I both (a) pay attention to where tall buildings are being built; and (b) have been to Cleveland numerous times. The funny thing is, being in a city, you rarely see its skyline. Driving in to the city from an exurb, you see the skyline; but in the city itself, you don't really see it much. Buildings at a human scale, that catch your eye when you're walking through the city, or that dominate the local environment of the city are the ones that you associate with the city.
