Mao implemented economic dictatorship in China. China would've been better if it had stayed away from the red menace and could've been a bigger ally to American than it is today. He is also indirectly responsible for the North Korean regime which is nothing more than a thorn in world relations.
I find Mao's ideology awful, although he did try to bring China into the ranks of developing nations in the early 20th century it was at the cost of millions of innocent lives. Not just that but the redistribution of land, forcing certain people to commit cannibalism due to the fact that there wasn't enough food to take care of everyone. In short, he wasn't a good man or leader. He had no morals.