I've also thought along similar lines before. In a future where STEEM was mass adopted, the average SP in any given account will become less and less. At a certain point, the majority of accounts would have less than 100 SP.

@fyrstikken has written before about the scenario of widespread usage and its consequences on price. $10, $50, $100+ per STEEM is easily possible in the long term. That would make the minnows/dolphins of today in a great position if they have patience.