As one of the voters (though my vote on steemsports is rather small -- at 30% vote power by itself my vote generates <$1 of reward), I'm pretty sure that I believe that the steemsports method adds more value to the platform than most of the other posts which would otherwise get rewards if steemsports didn't. At least the rewards are widely distributed to dozens of people, and it gives users who aren't themselves bloggers a way to earn (by playing games each day). Those who enjoy sports probably also find value in the fact that each steemsports post is also a sports blog post, generally well written, that discusses the game, players, etc.

I would like to see more competition for this type of post (distribution-oriented, though not specifically sports or gambling), that invites wide distribution and user involvement rather than just one blogger posting something that may or may not have any lasting value and receiving all the rewards. It may turn out that sports gambling is not the most popular format, though it does seem to be for now.