@smooth, downvoting won't really discourage gambling for "sure" shots, because otherwise the ROI on curation is mostly not worth anyone's time relative to the SP they have at stake. The only way to entirely remove the gambling groupthink calculation is to radically reduce or eliminate the curation rewards, which is what I would suggest.
As I explained to @bendjmiller222 in a comment on this page, removing the early incentive (in lieu of removing curation rewards) would just cause everyone to vote for the most voted posts after the fact.
The problem with current incentives to upvote is just how many people are playing the game. As long as everybody else is playing, the game seems worthwhile as the rewards are higher.
I wouldn't suggest removing the curation rewards completely, but the stake taken from the original post could be changed so that instead of 25% of the total, curators receive a limited amount. That probably wouldn't eliminate the incentive to upvote, but you might find less people voting this way if there seems to be less people playing the game.