There are no contracts between the community at large and Steemit, inc. Do you know of any? You say there may have been, but if so, where are they? How would the community have counter signed them? Who would have signed to represent the whole community?
To me, a "social contract" is not a real contract. A real contract is signed by actual people.
I'm not talking about a social contract. Legally binding contracts incorporating representations about the use of the ninja mined stake were likely formed between Steemit Inc and each person who signed up for Steem on their website as well as the other early ninja-miners.