All of his counter-argument are readily, and obviously, felled by variations on the same theme.
1.) Artificial intelligence is already getting smarter than us, at an exponential rate.
This is entirely irrelevant. Artificial Intelligence (a misnomer, if ever there was one) doesn't even have to be a factor. All that matters is that machines are purposed and sufficiently well programmed to do a specific task usually performed by a human. This is the exact same thing that happened in the industrial revolution. The only difference is that our machines and their programming are more sophisticated than in the past, and are therefore able to perform more sophisticated tasks that are usually performed by humans. As such, activities that need human intervention are slowly (and in some cases, quickly) dwindling.
2.) We'll make AIs into a general purpose intelligence, like our own.
We don't have to. Computing hardware is so relatively cheap, and the software cost so low, that we can have relatively dumb machines intruding to more traditionally human-driven jobs. Again, this is a continuation of the industrial revolution, but with only more powerful machines.
3.) We can make human intelligence in silicon.
Again, we don't have to. We need only create algorithms smart enough to do a particular job better than a human. This is progressing rapidly enough to be a concern right now. We have algorithms sophisticated enough right now to perform some intellectually challenging jobs better than their human counterparts. Specific machines and software to perform specific jobs.
4.) Intelligence can be expanded without limit.
Again, it doesn't have to. So called, "intelligence" isn't even required. Just raw processing power for a single task, with an increasing number of single tasks being defined and solved. This expansion is effectively limitless over sufficient, finite time.
5.) Once we have exploding superintelligence it can solve most of our problems.
Again, it doesn't have to explode, or to be super-intelligence. All it needs is to have specific tasks solvable in a manner that well exceeds human abilities. These small tasks need only be grouped and managed to have a dramatic, jaw-dropping efficiency that no human collective can match. That is much easier, and has endless examples from the 50's onward.
Replacing humans is the whole reason computers exist. I've watched it happen over and over where I work. Computer exist to automate tasks performed by humans, and to perform tasks that humans can't do. So, none of his arguments are in any way convincing. He is arguing from a perspectively completely disjointed from reality. It's not the threat of a single, large artificial intelligence that is the problem. The real threat is that of many small pieces working together to outclass humans.