He's a psychologist who wrote his book prior to the replication crisis in social psychology. I read "Thinking fast and slow" with a companion piece that detailed the most flawed parts of the book. I read that blog post before I read the book. There's basically no psychology you can read without some degree of BS in them so I love reading books which have already been thoroughly scrutinized. Some chapters were very well grounded, others like ch4 I didn't even bother reading.

I don't know where you got the impression that MOST of his research got undermined by that blog post when that blog post mostly took down a few chapters. If anything Kahneman impressed me for coming out of the replication crisis with not much more than a blown off limb. It would be great if Kahneman got everything perfect the first go of things but it was practically the point of his book that it's incredibly difficult to not make the exact mistakes that he ended up making.

The above posters general point is correct that the author doesn't really understand Kahneman's work, otherwise they would not have phrased things the way they did.