Interesting enough the main lie repeated in said article is one made by GMaxwell.

The Nothing at Stake Myth is Literally a Nothing to Gain.

The Facts are you need a Multistaking Client to even attempt a N@S,
no one has written one, because people that looked at making one realized it would create a PoW style system which actually gains the user nothing but wasting computer resources.

Fact is , if you have enough coins to shortly control the chain, then you are earning coins,
you gain nothing by trying to control the chain as your coins go dormant immediately after staking.
It is like this, say you are calculating a reality, which requires a % of CPU and Memory, now calculate paralleled realities for each fork that you are trying to dominate with your staking resources out to say 100 future blocks with each of those having parallel forks.
With every new parallel fork calculation your CPU & Memory requirements increase exponentially, evolving into another wasteful version of proof of work.

The Majority of PoS coins Destroy the Transactions fees, so dominating a PoS chain won't earn you anything extra.
Your rewards are all you get, and that is fixed by the code and time, even if multistaking was not insanely stupid waste of resources their is literally nothing to gain from it.

So let's end this stupid myth,
Gmax why don't you write a Multistaking PoS client and destroy all PoS coins,
Surely that will raise the price of all PoW coins for all PoW holders.
Unless of course you like to admit you were wrong.  

FYI:
If one really studies the PoW verses PoS debates.
One thing they learn is PoW has to end rewards and switch to a Transaction fee based economic model.
*Which causes all kinds of problems for miner profitability , due to the winner take all design in PoW.*

In PoS, Ultra Low Inflation Rewards can continue forever and by burning all transaction fees to keep supply in check.
This also allows a low fixed transaction fee model in PoS which is impossible in a PoW model that needs ever increasing fees to offset the loss in their winner take all ever increasing energy wasting design.