If there is a specific manner that allows people to vote in a fashion that doesn't seem like it's good for business, make adjustments. If I have a leaky roof, I'll fix it. Replacing a leaky roof before testing to see if it can be fixed is counterproductive.

This is my quote

How do you remove these problems while keeping curation rewards ? In other words how to incentivize people to vote for quality content instead of high paid content when you have curation rewards?

I am not trying to replace the roof, else I wouldn't have asked you how to repair it...

I've thought about improving curation reward but it's very difficult to incentivize people to vote for what they like instead of what the post will earn.
I don't really see how to improve the current curation rewards system because it is already very good at what its doing and every abuse problem has been thought out, but it is still a burden because the incentives are bad.

At this point the best would just be to give a fixed curation rewards to active voters ( say 30+ vote per day) in proportion to their steem power.

EDIT : Actually even a fixed reward is stupid as it would incentivize bots to vote which means a lot of the stake will be used by bots.
What we want like @timcliff said is a system where real active users are rewarded by having a bigger influence. ( since no more bots will be voting)