Just my semi-educated opinion - McArthur was a very good Emperor of Japan since it was a perfect compliment to his ego, and he made a good strategic call at Inchon. He wasn't completely lacking in generalship, his lack of preparedness in the Philippines notwithstanding, he just had such a huge ego he couldn't work well with anybody else.
As to his good press, just guessing that his political connections extended to members of the press.
As emperor of Japan, he screwed up Japanese porn forever.
