To the point of this article, the best product people were in fact respected by the tech team, and it made all the difference.
To design stuff. That's what engineers do (on the case of software, designing is also called "building" and "developing").
Engineers do not fix the problems of your organization. At least not while wearing an "engineer" hat.
> MBAs and project managers
Non-technical MBAs and project managers are patently unable to solve a lot of the organizational problems of engineering organizations. But well, usually yes, the MBAs are the ones tasked into solving them. I dunno why you included project managers.
Let's look at it as a bunch of people solving a problem which is too big for any one of them. Those people are different, they contribute different parts of the solutions - engineering, managerial - but they all have to cooperate to solve the problem, at least efficiently. If they don't, or don't do enough, for whatever reason, the solving suffers, possibly up to not happening.