Same reason why all cars nowadays look like cough drops. Aerodynamics.

It's a common feature added to many objects. My laptop, furniture, shampoo bottle, my backpack, my smart phone etc.. etc.

Whenever I see an aerodynamic building I just laugh, because when I throw my ugly smart phone into the trash, at least the aerodynamics makes it a bit faster while it's flying through the air. But buildings? Why? those things don't even move.

Actually, aerodynamics are really important for buildings, especially tall ones. https://en.wikipedia.org/wiki/Wind_engineering

(OK, you were probably being sarcastic! But wind engineering is cool!)

The Citicorp building in New York City was a particularly scary case of wind engineering (or lack of):

http://www.damninteresting.com/a-potentially-disastrous-desi...

> But buildings? Why? those things don't even move.

They are trying not to slow down the wind, so wind turbines will work well.

:)

That's what 3rd party cases are for.