Huh. I'd have thought that anyone who'd even read reviews of the TF
series would know that they fetishize the military. ROTF
, IIRC, even features an opening scene of Autobots helping the military blow up a foreign encampment not at all related to Cybertronians.
As I said, New York City is the most cosmopolitan and diverse city in the US. There really aren't many limits to what kind of characters of what origin could work in an NYC-based story.
Sure, about anyone can find their way to NYC, but how many of them can plausibly call upon the sorts of hardware and manpower resources the US military can? How many New Yorkers can plausibly provide big-ass robots or mech suits for the turtles to fight? Not too many Japanese citizens, I'd wager, and those are just wild guesses on my part. Again, I'm not yet endorsing the choice, but I don't think it's at all a mystifying one either. Guess we'll just have to see...