I don't think capitalism assumes profit to be the sole motivation for activity, just that it is the only one that works well for creating cooperation in the lar

I don't think capitalism assumes profit to be the sole motivation for activity, just that it is the only one that works well for creating cooperation in the large. Almost anyone, regardless of belief system, practices or can conceive of hobbies that are done for the intrinsic enjoyment of the thing. Some hobbies produce goods or services (building models or playing music) but some may not (reading). What lies at the heart of any economic system is the division of labor as a multiplier of wealth. A hunter-gatherer requires neither communism nor capitalism to motivate if failure to hunt/gather results in starvation. An individual's motivation need not go farther than that. Once you start dividing labor, you also need a way to incentivize people to pick the right labor. Communism supposes that people will continue to pick valuable jobs (here defined as ones that generate goods and services for the collective) of their own accord. Capitalism says that profit & loss will sort out who is doing what is deemed beneficial by others. This, if true, does imply something about human nature and not necessarily something good. That doesn't make it more or less true.