There are a ton of problems to solve, so why focus on one? The idea, I suppose, is that by focusing on a single "big problem", we could make very rapid progres

There are a ton of problems to solve, so why focus on one? The idea, I suppose, is that by focusing on a single "big problem", we could make very rapid progress (instead of making slower progress on a bigger set of problems). At its height, the US was spending almost 1% of its GDP on the Apollo program. Now imagine we could all agree on some other goal that we would spend that much money on. The hard part would be choosing a good goal, and then convincing enough people that it's the "right one".