Australian historians such as Peter Brune are quite critical of MacArthur. Peter Brune mentions in a number of his works that Mac ignored anything that didn't already agree with what he thought. That could be anything from planning an attack to intelligence. Once Mac had made up his mind there was no changing it and he had a tendency to ignore Australian intel in New Guinea and accept US intelligence even though the Australian intel kept turning out to be more accurate (which makes sense since the area was an Australian territory).

This lead to situations where reports would come from the front in New Guinea that there were more Japanese soldiers than originally thought and Mac would just disbelieve it because his intelligence said otherwise. Or it'd lead to situations where once an attack began that it was apparent that the maps of the area were incorrect, that the Japanese defences were set up different, etc and Mac would insist that the original plan be followed to the letter.

During the Australian attack on Gona Mac had been insistent that the Australians keep on launching frontal attacks, through a swamp against prepared Japanese positions. The Australian commander, Honner, kept requesting permission to conduct recon on the flanks and was denied. Eventually he disobeyed orders found a way around the Japanese defences and took Gona. Mac then went to the media and announced that it was his insistence of recon that won the day.

Mac would also tell reporters that he'd been to the front to personally lead when he'd done no such thing, obviously pissing off the actual commanders at the front.

Brune is highly critical of Mac surrounding himself with Yes Men so he'd only ever hear his own opinion repeated back to him. He didn't choose his staff for their experience and ability, he chose them because they wouldn't disagree with him.

Brune makes the accusation in his works that pro Mac historians ignore most of 1942 after Mac arrived in Australia because it just doesn't look good.

Edit - added the bit about Australian and US intel.

I can't comment on the greater body of his military career but I'm currently reading George F. Kennan: An American Life by Gaddis and Kennan/Gaddis are rather critical of McArthur in his capacity as overseer of Japan following the war. He's portrayed as arrogant, uncooperative, and misguided. Kennan essentially dupes him into agreeing to implement the Reverse Course in Japan rather than continuing to try and rebuild the entire country from the ground up on entirely American terms. While he is given credit for the naval landing at Incheon he is also given equal, if not greater, blame for pushing past the 38th parallel and causing China to get involved in the Korean War.

WOW! Cheers for the incredible answers! The depth of knowledge that you have provided is incredible and very interesting to hear about!