The clearest problem to me is the use of the curation system simply to harvest/direct rewards for certain users, rather than to reward any particular activity that might possibly be considered desirable.

The Hive account@fairlotto posts you point out serve a purpose beyond just collecting rewards, and any voting on them isn't in direct in exchange for rewards.

Running lotteries or contests based on people actually buying tickets rather than subsidizing the prize pool from voting rewards seems perfectly reasonable to me.