Where's my incentive to climb the ranks? If it becomes my job to go around looking for things that aren't worthwhile so I can give it a down vote, when will I get a chance to look for the things I enjoy... and how can I show my appreciation?

Also, your incentive to climb the ranks would be that you could actually influence rewards. The more SP you had, the more your vote would be worth. 100 MV would basically put you at the status of the highest whale, and you would have a large say over what got rewarded. Anything beyond 100 MV would give you additional 'moderator' rewards.

I did make an edit to the post though to account for users who want to use their first 100 MV of SP to remain a 'regular' user.