So far those proposing proof-of-stake have failed a simple test:
I haven't heard of one proposal that allows pools of peasants to be stake miners. Effectively these would function as cryptocities as there would be an incentive to keep cryptocoins within communities. This would create feedback loops and self-propelled microeconomies.

In more pragmatic terms, "fairness" is an arbitrary concept that is improbable to be agreed upon by a large population. Establishing "fairness" is no goal of Bitcoin, as this would be impossible.