Nice argument.
EDITS:
Block chains are all about public data and transparency. Everyone who has been online and maintained connection with the real public chain has no reason to trust or even consider an alternative chain that challenges the public record. It is indisputable which chain is the real chain and which is a secret the impostor.
What this means is that the “Nothing-at-Stake” attack can only be carried out against a new client with no prior knowledge. [consistent use of hyphens]
99% Ninety-nine percent of all businesses accepting payments will be using full clients that keep in sync at all times. [you don't start a sentence with a number]
Those that spout Nothing-at-Stake...
You have nothing to fear from the so-called Nothing-at-Stake attack. Let's [not lets] talk about the numerous risks of centralizing mining pools that have already executed a double spend attack on Bitcoin. Let's [not lets] talk about economic sustainability. Let's [not lets] look at the plank in the eye of Proof of Work before considering the relative spec of in Proof of Stake.