I think Gates is interested in low hanging fruit where he knows his money can make an immediate and measurable impact at a large scale. Malaria is a good target

I think Gates is interested in low hanging fruit where he knows his money can make an immediate and measurable impact at a large scale. Malaria is a good target because we know how to prevent Malaria. And realistically a lot of deaths can be saved with a relatively small amount of money, attention and coordination. Energy is complicated and will take a lot more money to solve then he has.