Bigger rewards while the price crashes because everyone sees it as a pay yourself scheme not much different than all other ponzi schemes? Buying steem just to vote on yourself is hinged on the end goal, which is to eventually cash out and return a profit, correct? If steem did not have curation rewards then this platform would have imploded long ago as surely no one would have invested, as you observed, simply to give others rewards. The same for downvoting, without it, this place would have become a prisoner dilemma in no time, where despite the curation rewards no one would risk voting for anyone else. The only way for this platform to succeed is by utilizing the mechanisms to encourage others to power up what they are rewarded and to invest by buying steem. If everyone were simply paying themselves, surely you can see that it wouldn't be sustainable, much like if everyone only voted for themselves, because none of that encourages anyone to power up or to invest. That's why the proposal is in place, that's why downvoting exists, that's why curation rewards are so important.