... what most users would want them to optimize for?
... what a critical mass of users would want them to optimize for?
... what you wish they would optimize for?
My Idea was to make the curator and the subscriber rate content, but to never use the mean rating. If you subscribe to someone you trust only his ratings and can adjust with your ratings (or likes, but not just clicks).
Currently I'm sadly not sure if I have the time to build a prototype alone. Let me know if you want to know a bit more though.