Many of his ideas were ill-conceived:

https://en.wikipedia.org/wiki/Four_Pests_Campaign

Mao was indeed a really bad administrator. It is said that he would have been remembered much more fondly if he died just after the success of the revolution.

Pretty much half of the decisions he made led to a disaster.

The rise of Xi Jinping in China suggests that the memory of Mao's mistakes has long since faded, not just among the masses but also among the leadership. All the procedures and norms put into place to prevent another Mao from taking control have been systematically removed to give Xi Jinping greater power. I think the process started with Hu Jintao, who also held several key offices simultaneously, but the accumulation of power under Xi seems more transparent and deliberate and therefore more naive on the part of the leadership.