Survivorship bias - yes; but I think it's still better than getting recommendations about books and productivity systems from people who do nothing but peddle advice.
Given the apparent lack of consistency (no book suggested by more than 3/100), the results seem pretty random. Not sure you wouldn't have done as well asking the advice peddlers for recommendations of other author's books.
No. If you see the quotes of the founders in the same article, a few have clearly discussed how the books had an impact on their business strategy. This is what I truly found insightful.
