I wouldn't generally trust a billionaire to make the humane decision for anything but that is not why I was surprised here. My starting position here is him asking a company to fire tens of thousands of people and lower the pay of more for a more profitable short term investment. I do believe that most people are selfish to some extent but I think people like this are more selfish and hence why my attempt to explain his seemingly more charitable acts from a selfish point of view.
Additionally, I think these people have so much drive to achieve power, it becomes aggressive to the rest of humanity at that point. Sort of "directly and consciously hoarding water for personal gains and comfort during a horrible draught" kind of aggressiveness.