Mao's estimated "kill count" is between 50 and 70 millions people.
How is that "much lower" than the US in the last 50 years? And how is that comparable? You can't compare a country with lots of different governments, politics and wars, with one dictator who managed to do this on his own in a far shorter time.
Trying to excuse Mao, surely the greatest murdered of all time far above Hitler and Stalin, is unacceptable. What's the next step? "Hitler was actually a cool guy if we compare him to the previous 2000 years of atrocities in the entire world"?