If nobody knows what is required to get 70% correct and their expectation (based on past experiences) is at 10%, then if they want to succeed, they'll work as hard as they can regardless.
Maybe the test is extremely long and challenging and basically no one will even score 50%.
That is actually the reality of capitalism. Basically no one becomes a billionaire and almost none of them could have planned for it.
You don't need to keep multimillionaires working; after a certain point, they add no new value. Just look at Facebook, after Mark Zuckerberg became billionaire, it was all negative-sum games. It would have been better if he had just retired to Hawaii and let someone else have a go. Why keep the guy under this illusion that he is still playing a fair game? He is not playing the same game as he was playing when he was in his Harvard dorm room... And even that game was way easier than the game that 99.9% of people alive today are actually playing.
