It's less about the act of reposting, but more so about the monetized reward of reposting content.
If you can repost your content (or someone else's content) and get paid for it at the same rate as putting effort into new content, should you? Why not do it twice and get twice the reward? Why not do it every day? Why not everyone do it every day? It's a slippery slope in my mind.
Sharing content I believe is fundamentally different to reposting content. We need to be cautious about the reward, not the action. People who "reposted" shakespeares content did not sell it to the same purchasers over and over. And they certainly did not claim to be shakespeare when they sold it to the purchasers, and pocket the reward. They shared the work, usually for free.