I think this characterization of engineers is off, and in a way that appears to inflate the value of the PM role. It’s taken from (a PM’s) ideal perspective of himself, where he is the gatekeeper to the business knowledge of the organization. They know the “why” and the engineer knows the “how”.
Now maybe at a huge organization, this ideology gets entrenched - but at companies smaller than (let’s say from experience) 300 people, this is neither correct nor best.
What’s best - I believe - is the increasingly popular concept of “product-minded engineer”. And, while I’ve not seen it coined, I’ll introduce “engineering-minded pm”.
What’s the difference? A lack of knowledge hoarding, healthier knowledge transfer and decision making, and reduced waste. I’m not even going to think or talk about increased velocity, just reducing the waste will naturally increase focus and take care of many other problems.