Part of what you're missing is that designers are closer to the user than engineers usually are, and the article relies on that link. I did support for many years, and I am very aware of the disconnect between what non-customer-contact engineers think users want, and what users actually want. Your customer-contact staff are an excellent barometer to the mood of your users, because they're actually looking at what's going on. And in the case of support and sales staff, they're at the pointy end.

And of course engineers are essential to a high-tech company. It's like saying lawyers are essential to a legal firm. But in a lot of tech companies, the engineers are insulated from users, or are even dismissive or abusive of them.

Also, the biggest tech company in the world was led from near-bankruptcy to "more cash than the USA" by not an engineer, not a designer, but a business guy. To make a great company - google, microsoft, whatever, you need hardcore business folks that can play the game hard at the highest level. Having a clean engineering setup is nowhere near enough.