This is how curation worked before rewards: people discovered great content online and shared it on their blog.
That had a monetary value for both: the curator built their following, depending on how good they were at finding great content. Sites like kottke and daring fireball are mostly shared links with minimal added commentary and have tens of thousands of page views a day. For the creator because additional visibility and thus potentially increased ad views and clicks.
In a next stage came platforms like reddit, digg, and then FB shares and Twitter. Posting the link again could have a monetary value depending on the reach of the "curator". And both on reddit and digg members have actively charged to share links, charged because they did have reach and would drive 30-50k views in 24hrs.
No,I see no issue in 5% earnings for those who discover solid content and share it to new audiences. Even less so if it means that the original creator of the post earns additionally.