Nvidia's coup was in getting people to switch to a different programming model and rewrite their code to achieve the necessary performance. Intel, especially in upper management, is stuffed with people who assumed that was impossible. And faced with new competition from GPUs, the only acceptable response to management was the many-x86, "you don't have to rewrite your code to get performance" approach which didn't actually work out.

It's not that Intel doesn't have people that recognize the issues, but rather the people who do have that foresight are drowned out by people who don't realize the game has changed. Intel, to be fair, does have the best autovectorizer--but designing vector code from scratch in a purpose-built vector language is still going to produce better results, as shown when ispc beat the vectorizer.

But Nvidia can also get drunk on its kool-aid, just as Intel has been. Nvidia's marketing would have you believe that switching to GPUs magically makes you gain performance, but if your code isn't really amenable to a vector programming style, then GPUs aren't going to speed your code up, and the shift from CPU-based supercomputers to GPU-based supercomputers are going to leave you happy. There's still room for third-way architectures that is anyone's game.