Currently, steem's curation rewards are hardcoded and capped to 25% of the author rewards. That is much less than what a author can earn by self voting on his posts (75% or above). This is one of the reasons why many authors are not curating posts and self voting a lot more than average.
In order to create the incentive to curate, steem should increase the curation rewards. If the curation rewards are capped to 40% then there will be more incentive to curate. There isn't much difference between 60% and 40%. This will make the platform more healthy and increase user engagement.
I saw another user in steemit suggest that curation rewards should be 50%. But I disagree with that cause I think curation rewards should always be less then the author rewards. Authors work hard to make content and for that they should get more then the curators.
This feature can be added by configuring the comment_options operation as pointed out by jesta.
Posted on Utopian.io - Rewarding Open Source Contributors