I like that you acknowledge that the innate human drive to create is at least as strong a drive as the profit motive, yet are only willing to accept that it is a sufficient motive in a "post-scarcity" society (whatever that is supposed to be anyway - there will always be scarce goods, that's the nature of the universe). You also commit a common fallacy when you imply in your first paragraph that communism preventing people from accumulating capital is an act of unjust violence and oppression - it is not, and that is so for the same reason that preventing people from stealing from others is not an act of oppression either. I suggest to actually read one of LeGuin's books, mostly notably The Dispossessed.