Late answer, but I see no one mentioned the whale experiment that was going on before HF19: basically whales didn't upvote a lot, and when they did, another whale countered the upvote with a flag. So basically the answer to your question: the money was going into oblivion!
With HF 19 and the linear rewards, the whale experiment ended, and the reward pool was quickly drained because of this. This is also why the rewards now are lower compared to the begining of HF19, regardless of steem price: there were so many upvotes and so few flags from whales, that the reward pool had to adapt and give less reward per upvote.