In fairness to MacArthur, wasn't he a pretty enlightened governor of Japan under occupation?
In some respects. Criticism can be directed at his policy of purging anything of Japans history from the 1890s, which gave the Japanese the opportunity to dodge any knowledge of the brutrality & criminal acts of Imperial Japan. The policy was the reverse in Germany, with descriptions of the horrors of the nazi regime included in the childrens education & otherwise made public. Even in the US the near extermination of the native peoples, the terror against African Americans, ect... is openly discussed. When I lived in Japan I was struck by the ignorance of the Japanese to their recent history and careful avoidance of that subject.
His post war economic policy for Japan has been criticised as well, with haphazard reconstruction of the infrastructure, and a lack of redevelopment of the work for the skilled trades.
Could he have been, well, less bad as President than people think?
Between his lack of experience in legislative politics, his inability to work with Roosevelt, Marshal, Nimitz... in progressing the Pacific war & his increasingly dysfunctional ego I'd think he would have severe difficulty in accomplishing much. A US president is not a dictator & to get anything done he has to be skilled at persuading enough Congress critters to support the agenda with budget allocations & law. Treating Senators who disagreed with him the same way he treated a corps commander or staff officer would have created trouble beyond his comprehension.