Absolutely no reason for it to be Long Island.

Except if the events in the director's life actually occurred there.

The actual production people must have been originally from nowhere near there. Filming in NJ is at least better to sub for eastern LI than Vancouver, LA or Toronto, but they got whatever details that were supposed to indicate LI apathetically not even close.

An early 60's NY license plate on Hutton's Lincoln? The production department makes a Real Estate sign with the town as "Long Island" - that's one mistake no one from anywhere near there would make. Long Island is bigger than a few states in population, obviously there's no town with that name. The Nevada zip code starting with an "8" instead of LI's "11" is a nice additional touch of apathy. The NJ trains didn't have too many NJ signs on them, so that was a little better. Nothing said LIRR, with all the dialogue about trains, though.

Alec Baldwin, who is actually from Massapequa - a town that happens to be on LI in the middle, would have known these things, but would have completely different things on his mind as an actor.