Let me just get this straight. Do you agree or disagree with the piece? Your commentary is a bit run on and I cannot make a lot of sense out of it.
Anyway, in some ways I can agree with the piece. Humans are quite surprisingly flexible in what they can do. I mean, we have jacks of all trades on this very forum. However, I also believe that AI will automate away many (if not most) jobs. The transportation sector will be hit by self driving trucks, banks by even more automation where people can do their own things without having to go to a bank. For example, in the Netherlands banks have gone from offices with tellers and everything to spaces where larger decisions are made, accounts are opened and closed (mainly because you need ID to open an account) and people who don't know how to use the computer system are helped via a local version of the very same computer system. No tellers needed, only a few advisers because the brunt of the info is online. But the core of what I disagree with in this piece is that there is no reason to suppose that the new industries that will arise cannot be automated.
So, let's explore that for a bit, shall we? Nowadays we have all kinds of industries that we did not consider automatable even just a few years back. Now we have computers doing image recognition, resulting in cars driving themselves, computers assisting doctors with diagnoses. We have machine learning, which has had and has a huge impact on various computer systems we use every day. Essentially, if it can be made into an algorithm, a computer can do it. This is not bad per se, and it will probably open us up for more joyful pursuits. But it does open up another can of worms, as our old economic system cannot work when only a few people have income (assuming new industries get automated away as quickly as they came).
But to get to (what I think) is your point. Converting to General AI will indeed be painful, but I don't think that the resulting AI will have a good reason to just kill off humans. We are not completely worthless, I mean, we still do things that AI can hardly replicate and we do it way more efficiently and effortlessly than AI can! Sure, AI programming will not be "just like now, but better!", but it probably also isn't the apocalyptic wasteland of Terminator or Matrix. We can adapt and we should adapt to the new reality, but as always, we don't really know what will be coming. All we can do is speculate and prepare for various outcomes.