I think you're reading some moral judgements in that aren't there. We have very little control over the future population of the world, especially over a 1 mill

I think you're reading some moral judgements in that aren't there. We have very little control over the future population of the world, especially over a 1 million year time scale. Nothing in the article says "it would be good for there to have been 100 trillion people in 800 thousand years", it just says there might be. However you tweak the numbers, unless you assume a much more significant depopulation than just the current 8 or so to 6 billion people, it's many trillions of people either way. Even with a massive depopulation, if human life continues until then the number will unquestionably dwarf the current population. So it's posing the simple question: If your actions cause pain for future generations, how many people will it effect? What's an acceptable number of future people to hurt for whatever you're doing now? This is a moral question, a kind of ultra scale trolley problem, not an answer.