I still believe we have more good people/stake than bad ones
I fully agree with that one right now, but I'm not sure what will happen when we will start to attract the majority of "facebook users". I fear there will be a "free money" mentality and it will be in the shoulders of the few to correct the greed of the many.
Rewards are free money, but it is very diffcult to secure a result or predict it. Rewards really amount to the payment for the effort, in a subjective assessment by peers, of the results of the effort. A combination of diligence and luck. It's no less fair or entertaining than a game of Poker really. It even shares some features in common with poker in that the 'opponents' (your competitor curators and creator) decisions are only knowable after the transaction has been made. Predictable votes are easier to front-run.
It's a fair concern, but IMHO it's over-concerned right now.