I totally agree that simply disabling self-up-voting can never work. There are too many ways to get around it, bots, sock-puppets, delegation, multiple accounts. So any option there is right out.

To expect it to be handled by community distribution is tough, because that requires people to give up voting power to remove rewards from someone else. Even if their goal was to increase rewards for other content, they could do that more directly with their power by voting that content up (probably).

It's a tough situation to tackle, but people will definitely generally act in their own financial interest. So expecting down-vote curation to stop it could be tricky.