It is a matter of personal taste, I suppose. Still, the concept of corner towers supporting the roof is a very interesting one, especially if you are planing to increase the initial 60,000 capacity in the future.
They wouldn't allow for expansion - if anything they'd restrict it. The San Siro was expanded for Italia 90 by adding an extra tier - the towers providing support for the new roof and access ramps.
You can see clearly that the San Siro towers are outside the footprint of the earlier expansion.
If you built straight up form the "royal box" towers they'd restrict the size of the upper tier.
I also don't get why you'd put the most expensive seats (with arm rests etc) in the worst viewing positions. Generally, corporate seats are sited around the halfway line where you get the best view of the whole game.