The author is making the mistake of thinking that just because he can show some areas were we aren't as far as we thought he has made an argument against AI.
Thats not how it works. We don't get to decide what is the right metrics. All we can see is that we keep making progress sometimes large leaps sometimes slow.
I always find it fascinating that we have no problem accepting the idea that human consciousness evolved from basically nothing but the most elementary building blocks of the universe and once we became complex enough we ended up being conscious yet somehow the idea of technology going through the same just in a different media seems to many impossible.
I know where my bet is at least and I haven't seen anything to counter that neither the OP's essay.
...yet. See my comment here: https://news.ycombinator.com/item?id=14770230
The hard thing is to predict the when, or even if, of AI. If it will happen, it will be a sudden, light-switch like moment. I don't think AI can happen gradually. At least the first artificially scentient entity will be a moment much like a singularity some love to predict in the near future...
But as to when that moment will occur, or even if, I think we have no real data that shows we are any closer today than say 10 or 30 years ago. Pattern matching, no matter how complex, isn't "all there is" to intelligence and conciseness.
EDIT: OP changed his reply from "will never happen" to "hasn't happened yet" while I was replying, explaining why mine might read a bit strange now... :-)
But our own intelligence happened gradually.
Every human genius would be out foraging for roots, perhaps reinventing the wheel or the lever, if it grew up without the benefit and influence of a society that makes greater achievement possible. Modern science and high technology that we attribute to human intelligence are really the products of a superintelligence (not to be conflated with consciousness) acting through us as appendages.
I think it's entirely possible (even likely) that all of the components of a new computational superintelligence already exist, but they are still "hunting and gathering" in the halls of academia or the stock market or biotech or defense...