In part this snub is do to the fact that after the CIB, New Guinea is probably next on forgotten US theaters of WW II. At least in part due to the fact that Gen Macarthur (the Montgomery of the USARMY) Did so much to insure that the only name ever remembered in the theater was of course His.
Dugout Doug was not only the Montgomery of the USARMY, he was the McClellan of his time. A self-promoting, credit grabbing narcissist.
Might the relative lack of memory of New Guinea from the American point of view be due to the fact that there was more British and Australian participation there than American? Same perhaps with China-India-Burma?