When NYC put 7000 police officers on extra duty, put up barricades, but the Trumpsters failed to show up. The made for TV, staged fiasco of 100,000 snarling Trump fans crashing police barricades wasn't going to happen.
The optics of no one showing up for the event would be even worse.
He should have listed 50 cities to protest in, told people he would be randomly selecting a few, select a few, then switch it up, then cancel after resources were wasted.