I agree with the author's central point, although I don't know if I would de-emphasize the importance of the visual designer to such an extent. I think a couple of the examples he links to (Google, Facebook) are outliers. They succeeded in spite of their lack of visual design because their products weren't just executed well; they were executed extremely well. Generally speaking though it takes a bit more finesse in order to make your users feel at home using your product.
With that said, I agree that if the core product isn't well engineered then no amount of lipstick on the pig is going to make it usable. You can paint rust any color you like but it's still rust.
You could add eBay, Amazon, Craig's List, Yahoo, etc. I don't really think they are outliers - if you offer a product with real value, lack of design may have an impact, but the value you provide to customers will vastly outweigh it.
Not that I think design should be ignored, but sadly some of the giants have ignored it and done remarkably well regardless.
Yahoo IMO survived based on sheer inertia and likely based on its one-time command of at least a large portion of the online advertising market, and email. Certain site segments were pretty innovative (Yahoo Finance was a great resource for a while).
In 1997, Yahoo offered real value (it made sense of the Web). Even in the early 2000s, ditto. The problem with the real value proposition is that if someone succeeds in providing realer value, so to speak, you're sunk.
CL is a very interesting exceptional case. I'll note that they've had a designer position open recently.
With that said, I agree that if the core product isn't well engineered then no amount of lipstick on the pig is going to make it usable. You can paint rust any color you like but it's still rust.