I’ve read kahneman several years ago, and what I remember is somewhat different from what you state. I do not recall him using the term “irrational.” The word is vague, and can mean different things. What he and Tversky demonstrated is that we usually rely on “rule of thumb” thinking, a simple minded, fast thinking that often lead us astray. It might have worked well enough eons ago, but it is dangerous in today’s complex, rapidly changing world. You may call it “irrational” if you like, but this is not Freudian irrationality.