I don't think that's necessarily what the author is trying to communicate.
First of all, "If I am looking for a co-founder, who that person and their very unique combination of skills, perspectives, etc, matters a ton." Is that not just a well defined slot by another name? It sounds like your whole process is slots from conception to death.
"Obviously the person can do that in their own way to an extent", can they? This feels like a platitude. I can't speak to the SRE roll but most places I've worked you might get to choose from a list of pre-written algorithms and a few small UX details. And when you talk about collaborating on larger problems most individuals don't usually even get a choice of code style.
At a mature company I will agree that no, you shouldn't be hiring SRE's for product insight. Unless they fit into an insanely small bucket insight into your product is well outside of their scope. A contracting firm like McKinsey & Company would be a better fit for that kind of guidance. But tech insight? yes, you should be getting that from your SREs.
Also your example "insight" just feels... bad faith.
It's very possible I read into your comment to much and you were just saying "it is what it is". And I agree, it's just that I also think... https://yarn.co/yarn-clip/b097417f-9a28-4369-af3a-6739f1d361...