Nxt has been running over 2 years and you are now soapboxing the same arguments that have been refuted over and over.
This particular one has not been refuted to my knowledge.
In the impossible attack you are imagining, many user accounts would cease to exist, which would clearly indicate to any normal user that they are on a fork.
That's not true in the least; in fact, nothing out of the ordinary would happen unless the attacker started abusing his power; he could just sit there producing blocks all by himself forever, taking 100% of transaction fees.