AFAIK a ponzi scheme is getting money from someone then promising a future investor X returns, then go for a bigger promise to another future investor X+nP returns, then higher and higher? Nothing of that sort here.. also lack of refferal fees and upline/downline incentives.

The way I see it, Proof-of-Authority for the Crown would invite those with those agreeing with the notion of basic income (by protecting workers as top duty) and using resources to achieve the Crown's goals / vision. While Gnosis and pretty much any PoS setting is market-driven decision making (as the whole decides based on net votes), PoA is individually-driven decision making - doesn't affect the entire market, but only their "realm". It's an efficient direction of energy compared to PoW and activities coming from the million of divisible PoS accounts, but if most crownholders are imbeciles with their end-game, then we may have a problem.