Completely agree with you here. The average content consumer will never be a whale, why would they be? I don't believe we will ever motivate the average Steem consumer to power up sizable amounts of SP beyond $50 worth. Let's say they buy $100 in Steem today and get 333 SP, that's still just in the $0.01 upvote range and they're only getting 25% of that amount. If they upvoted content optimally with no less than 300 upvotes per month, exactly 10 upvotes per day at the end of a year they would have around $9. Would that be worth it to you?
I'm not saying we do away with curation rewards, but if we have to diminish any pool in favor of a dev fund, I'd choose curators. Honestly, I believe the concept of Steem appeals primarily to content creators hoping to earn on Steem, not content consumers that don't want to produce content. The problem for why we're not taking off all that fast is that we are not intriguing content consumers enough. But I don't think curation rewards are going to solve that, I think we have to empower them and give them access to cool stuff. Steem Monsters is one example of doing this well, but we need a lot more cool features that make Steem fun for audiences.