The system should always account for the nature of humans. The curation should be worth it even without some vague goal of making the platform better.
I upvote other people if I like what they are saying, but I have no shame in upvoting myself as well, since after all both upvoting yourself and others should be to your best interest, otherwise what is the point.

I think tying curation rewards to author rewards would be better, remove SP curation rewards, instead provide some other token that expires every week that depending on how much you earn will either decrease or increase the rewards on all your own posts.