There are a large number of assumptions built up around the singularity concept and CPU's are not getting exponentially faster so at least one of them seems incorrect. Honestly, the hardest problem IMO is the idea that intelligence is fungible and twice as much of it will provide anywhere near twice the result. The real world is fuzzy and thinking faster/deeper only get’s you so far.
Let's say we can build a machine smarter than a single person, that’s a long way from building something smarter than humanity so there is not a quick kick off to infinity. Now let's suggest we build a billion of the things and they are all smarter than the average person. Nothing says you can get anything close to a linear feedback between the intelligence designing an AI and how smart the AI is so there would not necessarily be a feedback loop to keep making more intelligent systems. etc.
When talking about about computation the argument is usually presented as exponential increase in processor computational power (FLOPs/MIPs) per unit cost not processor speed. Even though processor speed peaked recently computational power per unit cost has continued to increase.
Economics drives an increase in computation per unit cost not processor speed. How the increase in accomplished is irrelevant.
Aside from that, the difference between one human and all of us is only 2^32 - so if you can place the intelligence of one human on a chip, you'll be able to do the same thing with all of humanity 64 years later. And that's ignoring things like reduced costs per chip / using multiple chips for the same price.
Well first of all, we all know the limitations of exponential growth in the real world. What does 'enhancing capability and intelligence to an unimaginable scale' really mean? It all strikes me as uselessly fuzzy and mystical. Good for pop 'science' articles and sci-fi speculation (which, don't get me wrong, is fun in and of itself) but not terribly useful or informative otherwise.
Why not?