But is it really that easy to own the majority of nodes ? You don't just need the majority of nodes but the majority of nodes that are voting in any given round and to be eligible to vote in the first place also costs, stake or PoW (I think zerotime is PoW/Pos right ?).
That's what I'm trying to establish. As far as I can tell, there isn't any real cost (neither coins or electricity) to obtaining a majority of nodes, but I'll wait for fusilier's reply.
If getting majority of nodes is easy, then the incentive to get the majority and gain financially from the attack is high. And if the incentive is high, then there will be many who want to profit from that and try to get majority of the nodes. But from this follows that getting the majority is not easy anymore.
So if the incentive is to short the coin, then they are all competing to help each other. So the cost will be low because they can see the attack working before they get the majority individually.