The thing is that PoW "works" even in the case where Satoshi-equivalent has most of coins, as the transactions are controlled by the mining power and new coins will be distributed through mining. With PoS, if founders hold most of the coins, then the scheme does not work as they de facto arbitrarily control the transactions and there's no way for a community to get that control unless they hand over the coins - thus, in PoS (unlike PoW) the founders need to solve the distribution problem before the scheme can become useful.