I saw it from the other side, "why on earth would humans not choose to uplift" - given the contextual quite reasonable expectation they could just ask and receive. The real problem with that universe is not a lack of things for humans to do, but a lack of things for anybody to do. Minds are hardly any better placed. I could waste my time as human dabbling uselessly in obsolete skills, or as a Mind acting as a celestial truck driver and bored tinkerer on the edges of other people's civilizations - what a worthless choice.