In his book the singularity is near he talks about all the criticisms and his rebuttals to them in the last hundred or so pages.
He also talks about how manmade disasters (cold war, WW2, great depression) didn’t seem to slow or stop progression of the exponential trends in science that he has been seeing for the last 100+ years.
A meteorite could put the brakes on it (for a while), but one isn’t expected to hit anytime soon. We are supposed to get a close call in the next 20-60 years, but the odds of that one hitting are extremely low, a fraction of 1%. And within the next few decades we may have working tools that can push meteors away from earth. There are already several designs for meteroite defense systems, but they are not being built or funded yet.
In my view, once human intelligence and the g factor (creativity, pattern recognition, innovation, comprehension, working memory, long term memory) are no longer limited by biology then everything will take off. That is more or less the singularity point IMO. I have no idea when that’ll happen but I assume in my lifetime sometime since I will be in my 80s in the 2060s.
Sam Stone’s criticism of the low hanging fruit its good, but Kurzweil addressed it with computing power. He claims exponential curves follow more a succession of s-curves with flat growth, rapid growth, then flat growth. The exponential growth in transistors is the 5th exponential curve for computing power according to kurzweil with older technologies (vacuum tubes, relays). He predicts a 6th technology soon as transistors reach their physical limits.
A problem I have with his predictions on AI and transhumanism is I do not know if we even know enough about the brain to determine if we can model it with a computer of X capacity. I do know there have been computer models of various parts of human and animal brains however.
Also a criticism of Kurzweil is he only predicts where our capacities will be in the future. He predicts how much processing power, RAM, drive capacity, base pair readings, etc we will have. But extrapoling that to determine what we will do with them is hard. The playstation 3 has the processing power of the most powerful supercomputer on earth did back in roughly 1993. Even if you could make a prediction that a gaming system would have the processing power of the world’s fastest supercomputer in 15 years that doesn’t mean you know what it’ll be used for. We probably use more computing power for gaming graphics in 2009 than were used in all medical and scientific research combined in 1998.
So my point is I agree with Kurzweil’s trend lines. However I do not know if you can extrapolate that and say ‘we will use that scientific capacity to achieve X’.
He has written older books, check out ‘the age of spiritual machines’ which made predictions for 1999, 2009, 2019, 2029.
Some of his predictions for 2009 are personal computers implanted in rings, translational software being everywhere, people using speech recognition rather than typing. For some of these issues we have the technology to achieve these things in 2009, but nobody really wants them. We have speech recognition software. And a person probably could get a computer in a ring. But most people aren’t interested.
Other predictions that happened or are happening include using steady state memory more and more, wireless communication, most phones being wireless.
So hloking at his predictions for 2009 many of those predictions are happening but they are in the early stages (telemedicine, translational software, steady state data storage, self driving cars).
So Kurzweil’s predictions don’t always happen because there is no incentive to make them ahppen (who needs a computer in a ring) or they are in the early stages when he feels they should be mature.