The problem with this is a lot of these statements came out during the red scare as a way for the liberal west to distinguish itself from the communist east. Saying "Mao killed tens of millions" is like saying "Capitalism kills tens of millions" because people around the world don't get food for free even though we make enough food to feed everyone. They are similar because the argument is essentially "the central planning lead to famine" which points to a failure of the ideology, not an intended result of the ideology.
Stalin and Mao were brutal and both directly killed and imprisoned between them killed millions who didn't agree with them, but the number is a couple of orders of magnitude less than the oft cited tens of millions to hundreds of millions. It doesn't excuse them of the violence they subjected to millions to, but statements like this make them seem worse than say the result of fascism which has been something that fascists (along with holocaust denial) use to disparage actual communists to benign and reformist social democrats whilst lifting the historical record of their ideology's crimes. For example, look at the nonsensical "universal healthcare is communism" rhetoric in the US.
Stalin and Mao were brutal and both directly killed and imprisoned between them killed millions who didn't agree with them, but the number is a couple of orders of magnitude less than the oft cited tens of millions to hundreds of millions. It doesn't excuse them of the violence they subjected to millions to, but statements like this make them seem worse than say the result of fascism which has been something that fascists (along with holocaust denial) use to disparage actual communists to benign and reformist social democrats whilst lifting the historical record of their ideology's crimes. For example, look at the nonsensical "universal healthcare is communism" rhetoric in the US.