What's crazy to me is that the more modern 4th down play-calling statistics has been known for at least two decades now; I first heard about it from my stats teacher in high school.
The issue is that making the right call and it not working out would reflect more poorly on a coach than making the more traditional call and playing worse. It reminds me of the saying "No one ever got fired for buying IBM".
Five Thirty Eight has written a bit about this in the past. That's pretty much what they said. No one remembers the risky play that paid off or the safe/expected play; they remember the risky play that didn't pay off.
