Yeah PoS just increases the holdings of the largest holders the fastest.  So we're back with the wealthiest getting wealthier the fastest by default.  Maybe DPoS (Delegated Proof of Stake) could work where chosen and favoured individual coops run the staking nodes only.  Which are decided by a vote held by a FairCoop DAO or similar.  Say where the FairCoin DPoS DAO votes to decide which project is adding the most benefit to the ecosystem.  So then get's the right to run one of the 101 equal delegated staking nodes. 
Staking can now be done on a RasberryPi and they only use about 5W iirc.  It may actually be profitable to run a 24/7 node.  So the staking profits they earn could be used for supporting FairCoop projects only.  After all electricity and running costs are removed.  I personally would provide a Rpi and run a not for profit staking node.  Where all staking turnover after running and hardware costs are put into Coopshares Investment Fund (CIF).  And all profits from that reinvested back into the CIF.

Node count does look to be increasing now though along with the price and market cap.  I think there was usually around forty nodes at any one times.  And today there's over fifty currently.  Looks like more users are currently being tempted to start staking.