The only viable solution in my opinion is a software one. How can someone who has invested in steem be expected not to garner all the profits that an investment offers? It would not be my approach, not being a self voter, yet they cannot be blamed for what the system allows.

A simple limit on daily rewards in relation to an agreed percentage of the reward pool should do it. What would be interesting is to see what kind of Witness support such a fork would receive. 😎