The point is if you sum up what people would want to do with their time, there's no reason to expect that in any way corresponds with what the allocation of res

The point is if you sum up what people would want to do with their time, there's no reason to expect that in any way corresponds with what the allocation of resources should be to keep the engines of the economy moving / achieve maximal societal benefit / whatever. It's a classic tragedy of the commons situation.