I agree with the OP, however I do see @krnel's point about the manor buyers and sellers of attention are matched in that it isn't as direct as the OP stated.

Opportunity costs are the risk, as well as any time devoted to posts, curation and comments contributed. I am a perfect example of a steemian who has only invested his time to gain what I have here. I am fortunate enough that I've had friends "from a past life" that are whales here who have found value in my contributions and signified that with their attention.

This platform is an experiment. Whether my choice to participate in it will pay off better than other opportunities I might have invested my time in remains to be seen, but I am optimistic and still here because I believe in the hypothesis the experiment is based on and the integrity of those conducting it.

Unlike a scientific experiment however there are no well defined controls and rigid metrics. It is in actually more of a data gathering exercise where various hypotheses are evaluated and further hypotheses and conclusions are drawn as data is gathered. The conclusion, if there is one, might be characterized by answering the question, "Is the steemit project successful?", and even that is not an objective metric.

The whitepaper is not a contract with rigid terms and conditions. How close is the steemit implementation currently to what is contained there? Has the project adhered to the roadmap? Were the milestones stated in the roadmap adequate to measure the progress of the project while staying true to the fundamental principles expressed in the whitepaper? Have the project's creators communicated the lessons learned and conclusions drawn to the community?