Even in cities that rationally justify tall buildings, the "tallest building" competition is always about showing off. They set the records with tall spires on top that don't have any usable floorspace.
Yes, the spires on top of rationally justified buildings is showing off.
In OKC, it's not just the spire but the entire building that is about showing off. The rationale is missing --- which is why I doubt it will ever be built as proposed.