That was the first thing that struck me, the 'workarounds' stagger belief, but they seem to be casually dropped in (?).

If I were in a situation where my company was contemplating implementing building our own registry/network stack, then the benefits of using a cloud provider are gone, and I would have considered moving to another provider... not saying "I can fix him". This feels like a sunken cost perhaps that is the right term.

Well for folks building out cloud infrastructure, building your own networking stack and registry is a good way to achieve platform independence, without which you'll be left at a disadvantage and vulnerable to the whims of cloud providers who may or may not extend volume discounts, thus indirectly harming your ability to compete.