Not sure I agree with this. The article compares extremely low-fidelity wireframes with very high fidelity mockups. You don't have to choose between one or the other. Tools like Balsamiq allow you to create mockups that give a better approximation of the real thing with substantially less work.

I'm not saying you shouldn't create high-fidelity mockups, but get the usability problems solved first in a lower-cost environment. That could be as simple as a whiteboarding session or using index cards. You should be excited for a product/site not only based on how it looks, but what it does.