Why isn't Mao Zedong as renowned as Stalin or Hitler?

He caused the deaths of between 50 to 70 million people. That is utterly horrific. Purges, labour camps, great famines (he decided to dry rivers.....why?) all of this in a matter of 15-20 years. why the hell isn't he as famous as stalin for instance. It's ridiculous. I know they're both m murderers but Mao's death toll is disgusting. I just find it strange is all. Any suggestions why?