You seem to be contradicting his point, but as far as I can tell you're proving it.
The fact that you see such a stark difference between a first-class network engineer and the work of lesser mortals is proof that they aren't fungible.
I'll also point out that you have, perhaps unintentionally, changed the topic from design to maintenance. We're talking about product creation. Some people like to pretend that all the design happens in the head of the person with "designer" on their business cards. But anybody who has spent time in a team making great products knows that everybody is involved in design. It can't be otherwise, because design happens at the intersection of desire and possibility, and the technologists know the possibility space more deeply than anybody else can.
That a well-designed network can be easily maintained is demonstrates the great design skills of that first-class network engineer. That there are long periods in a network's life when design skills aren't needed isn't proof that technologists are interchangeable; it's proof that they aren't.
The fact that you see such a stark difference between a first-class network engineer and the work of lesser mortals is proof that they aren't fungible.
I'll also point out that you have, perhaps unintentionally, changed the topic from design to maintenance. We're talking about product creation. Some people like to pretend that all the design happens in the head of the person with "designer" on their business cards. But anybody who has spent time in a team making great products knows that everybody is involved in design. It can't be otherwise, because design happens at the intersection of desire and possibility, and the technologists know the possibility space more deeply than anybody else can.
That a well-designed network can be easily maintained is demonstrates the great design skills of that first-class network engineer. That there are long periods in a network's life when design skills aren't needed isn't proof that technologists are interchangeable; it's proof that they aren't.