^^^Well maybe it's an East Coast thing. Between NYC, Atlanta, and now Philly, nearly every single supertall on the East Coast has some sort of spire (except for the 2 latest resi towers in NYC). Aside from Trump Chicago, the supertalls there and in Houston, and the supertall and "near supertalls" on the West Coast that have already been built are relative monoliths. Could have been an era thing, as well. Everything built west of the E Coast that is tall has been a product, more or less, of the 70s and 80s.
Trump Chicago is a "cheater" too, but the thing has 98 floors that exceed 1,100' in height (basically to the tip of the spire for CITC). There are just so many taller buildings out there, it rubs me wrong when a basic 850-900' building is all of a sudden the "tallest."
As a skyscraper nerd, I know I'm not the only one that feels that way.
If you type in the Diagrams tallest buildings in US and Canada and search by "roof height" as criteria, you can see how many buildings there are in NA that are basically the same height - that is, once you get outside of NYC/Chi, there really isn't a clear "tallest" (going off of pages 1/2). By straight up appearance, it could very well be the Salesforce Tower since it will maintain its exterior structure straight up to 1,070' and the next guy is US Bank in Los Angeles. By top floor, it's US Bank in Los Angeles and there are a ton of buildings with top floors >900' but less than 1,000' (iffy if CITC/Salesforce are really included in that or if the former is somewhere between 850-900 and the latter is right at 900). By technicality it's CITC.
http://skyscraperpage.com/diagrams/?searchID=65825205