You buried the lede. Death per unit time is extremely important. And yes, huge numbers died of starvation as the result of revolutionary, utopian (and insane and nonsensical) policies. But the starvation deaths were the direct result of the violence and insanity. The two cannot be decoupled. So, I certainly would "count" them. I think most people would.
Is there an argument about how the deaths per unit time went down in those countries post-revolution?
> many of those who died post-revolution would never have even had the chance to be born
I'm not ceding this point, but hypothetically, by your logic, these were just bonus lives whose horrible ends shouldn't count?
> Tens of millions of people die of easily preventable deaths
Yes, this is the default state of nature and thus humanity. Violent, cataclysmic revolution is almost never the best (or even a good) solution. There are limited examples of success, but what sane person would bet their life on it?
I think, fundamentally, the problem with violent revolution is that its leaders are most often ideological zealots who are ill-equipped to lead a nation. They tend to think the same tools that gained them power (violence) will yield effective results in governance. Or, and I think this is a more likely explanation, they are probably just sociopathic, power-crazed murderers.
> Mao's derangements are estimated to have resulted in 45 MILLION dead Chinese.
Both of these death estimates are primarily due to starvation (not murder and not the result of violent revolution decades earlier) and are based off of differential estimates of population (ie. counting declining births as deaths, etc.).
Most importantly, they are not comparative with famine deaths prior to these revolutions under the feudal system. Integrated over time, those deaths almost certainly outnumber the deaths due to these events. Moreover, many of those who died post-revolution would never have even had the chance to be born in a feudal society given how many children died of starvation etc. during those times.
Tens of millions of people die of easily preventable deaths (no water, no food, etc.) in the status quo every year. Those numbers were even worse under feudalism. Do those not get to be counted against the non-revolutionary status quo?