your absolutely right, the contribution to the Steem pool is heavily concentrated on stakeholders. 334 Million virtual supply and 200 Million are staked. In the tulip bubble, the biggest contribution to the price came from the stakeholders. A stakeholder-focused system is a ponzi-scheme. A business can only be sustainable when it is creating value to customers.
The interdependence goes from plankton to whale. This has nothing to do with Marxism. There can be plankton without whales (this was Billions of years the case), there cant be whales without plankton. The economic value and the attractiveness for investors comes from a product value.
Most of socialmedia exists without curation. Heavy used platforms like Reddit and 4chan exist without any economic incentive for users. Right now the use-case of curation isn't even proofed (many quality authors here are scientists and good paid people doing blogging for a hobby). In the special case of Steem(it) your point is in fact very important, it's more a chicken-egg problem because the selling point is having curators ... this makes the problem so unique and hard to solve. Anyways thank you for your input! It's a very special situation I wasn't that aware of.