I think if CSW & nChain do hire more hashing power to commit 51% attack they would openly expose themselves as enemies of Bitcoin & no one would ever trust them any more.
CSW has a small fraction of the total hashing power. If miners join him and they collectively get more than 51% then the minority hashrate IS the attack. That's Bitcoin.
The ppl who scream "he's trying to take control!" don't know how Bitcoin works. For it to be an "attack" CSW has to be willing to lose everything. If he's king and he sucks - bye bye!
But to be fair, ABC with their new op-codes seem to want to do it as well. If either side added replay protection I wouldn't consider it as an attack, but neither side wants to do this
It still is. But the difference is that BCH ( the ABC devs actually ) volunteerly put replay protection into BCH so that the transactions could not be replayed.
The truth is, if you're deploying hashing power pointed at a certain implementation you're merely voting. With no replay-protection it's a winner take all election.