i think he's saying centralization is inevitable with most kinds of PoS.
If that is what he is suggesting than it is odd statement to make as it is trivial to design an algorithm which forces or encourages decentralization, even with PoS. What is tricky is combining the right security and incentives as well into the consensus mechanism.
I.E.. having Bitcoin incorporate a hybrid PoW /TaPoS algo where either some of the transaction fees or mining rewards aren paid to full nodes/or p2p miners would both encourage decentralization and make Bitcoin more robust.
I already have some concerns with Vitalik's proposal and am adding more concerns as I review it further but would like to hear more specific concerns rather than knee jerk reactions and generalizations(not coming from you BTW)
It is indeed possible that PoW is superior to everything else and Satoshi got it right the first time. What I find interesting and concerning is that many people aren't even willing to test or study new consensus designs. I have a long history of attacking PoS and many alts in general and am making a very reasonable suggestion of entertaining an idea and studying Vitalik's proposals followed by a very conservative approach of incorporating this algo into an alt or sidechain so it can be tested over the course of years before even thinking about discussing a hardfork and this is the reaction I get.
There appears to be a sense of protectionism, reverence and faith towards Satoshi's original code, which is silly because most of his code has already been thrown out or changed.
My criticism was directed towards current PoS implementations, where it's not the reward scheme that bothered me, but the fact that stake maintains permanent share of control no matter what, that's the recipe for stagnation and eventual collapse of the system. If you like the words "economic stimulus" you might hear a lot of that in the end game scenario of current PoS implementations.
The alternative mechanism seems to be proposed with PoI, but sustainable network effects might become new dangers of centralization there.
The point with PoW is that money needs to be simple, so that everyone can understand it, don't fix if it ain't broken.