[GuiA]

Ray Kurzweil has been discussed several times on HN, I recommend diving in archives to read in-depth conversations about the topic with arguments from both sides.

But to summarize what a lot of smart people say about him– he hasn't produced any original research in the past decade or so, and his latest "revolutionary" book contains a lot of information that neurobiologists consider either plain out wrong or grossly over-simplified. Mitch Kapor called his ideas "intelligent design for the IQ 140 people".

It is also worth noting that the timeframe he lays out for most of his predictions about singularity-style technology ("computers that feel and love", "eternal life") seem to match the boundaries of his natural lifespan (i.e. in the next 30 years). Some have seen here the signs of a man who's getting older, terrified of death, and trying to convince himself and everyone else that he is not doomed to go through the human condition.

As you highlight, he has produced a lot of great things, but it is not unheard of for brilliant minds to become quite kooky in their old age.