the shots we see on TV show nothing but heaps of 2x4's after these storms.
Structures that are heaps of 2x4's after Ike probably weren't much better before Ike. As mentioned, Ike was a *powerful* storm but not an *intense* storm.
(a picture of a house with no damage isn't dramatic, and press photographers get paid for dramatic photos)
I think the usual problem isn't aerodynamic stress of wind simply blowing but rather impact from wind-blown debris. In other words, engineering a structure to withstand Cat 4 winds won't automatically result in a surviving structure unless it can also withstand an impact from a cow at 40mph.
The main non-impact damage houses used to take from these storms was having the roof lifted off (gravity was about that held them on). Building codes have required "hurricane clips" for some time. I think builders actually comply these days though we'll see...