I think we can all agree that "use humans for raw energy" is a really stupid idea, and sounds exactly like someone dumbed stuff down. FFS, a small Rickover fission reactor the size of a van (1950s tech) produces the same amount of heat as, what, 200 000 human bodies? (And why humans, with all the complex support systems? Why not a heap of compost, if one insists on bio-source?)

Whereas using our brains for compute (in the background, or during REM sleep) makes perfect sense; power efficiency is excellent.