Good to see that this issue is still being thought about and discussed. It was quite clear from the beginning that PoS systems are vulnerable to tyrants simply because more money can buy more influence. A very very old mechanism that blockchain technology has not yet solved. The reasoning is that wanting to centralize Hive now to some few powerful players people would have to sell their stake voluntarily at higher and higher prices, but it seems there are enough bad actors who have never gotten rid of their huge stake that they still in effect hold control over much that's going on here.

I feel the only way to overcome this would be swarm intelligence and courage on part of the individual. Same as in society at large really - risking our own well-being on the individual level to overcome tyranny on the vaster scale at large.
I really have to read up on the pob discourse, cheers for the reminder