[bhupy]

With PoS, withdrawing your stake (read: disposing of your holdings) withdraws your ability to act as a validator. And pretty much every mainstream PoS implementation imposes a delay on stake withdrawal to give the rest of the network time to make sure that whoever is withdrawing their stake hasn't already validated fraudulent transactions.

[gruez]

That's still fundamentally a weaker system, no? Specifically, still possible to double spend, the only difference is that we assume that the network wouldn't accept block re-orgs that are that long.