There are a couple things to criticise Trump about.
This is not one of them. He is completely right about this.
Which is why I defended Trump on Newsmax TV a few days ago on this...that while Trump was not correct in saying thousands and thousands were celebrating in the NYC area, he was essentially right that much of the Islamic world WAS celebrating - and that's far more important than how many were celebrating in Jersey City versus how many were celebrating in Detroit versus how many were celebrating on "the Arab street."