de facto:
I just believe the captain over reacted in a somewhat non normal situation but what i am most worried about is the personality of such pilot and the risk he took just to make a point, that declaring an emergency gives you the right to engage other traffic into a potential lethal ending.
That is a tad speculative and contrary to the layout of the airport. Check an airport diagram for the relative position of Runway 22L/R and Runway 31R. AAL 2 was visual, had Runway 31R in sight, and was aware that it was not being used (even though a very strong wind was right down the runway). It sounds to me that he had made an assessment that his safest and quickest course of action would be a left turn to a short downwind, base and final to 31R. Of course, this could have conflicted with traffic landing 22L or R, or it may not have. That conflict would have likely been the same had the controller mucked around with AAL 2. But, there was likely no traffic conflict south/southwest of the airport that the controller's heading assignment would have resolved.
I suspect the captain of AAL 2 sensed a "Long Island Tour" because of the heading assignment when a short circuit downwind, base, and final, in visual weather conditions, would have complied with the declared pilot's (read priority aircraft at this point) plan.
We still don't have the facts as to AAL 2's actual fuel state. Could be he has flown into JFK enough to recall Avianca in 1990 and how that was handled by the tower and the TRACON. Heaven forbid he may have acutally read that accident report.