Some of the happiest and most satisfied people I know are academics who work 80+ hours a week because they love what they do. You don't need to sacrifice health to work more than 50 hours a week. And realistically there is no long term health damage from what he is doing. And yes you can trade money for better health, though in the first world you rapidly hit diminishing returns but if your sleep deprivation can make the difference between being able to afford good health care or moving to an area with less pollution it absolutely can trade off like that.