Le Deeper History

 New theory or new myth? I'm going with it regardless.

 China-style government causes ninjaification. You can already see problems cropping up after 1s of thousands of years. It will be obvious after 10s of thousands. They will become first india 2.0, then africa 2.0 This process is irreversible, as we'll see. 

 Fire was invented about four million years ago, and made ergaster evolve into erectus. Throwing was invented about two million years ago, and made erectus evolve into sapiens. The oldest known sapiens remains are about 200,000 years old, and ice ages only last about 100,000 years.

 Weird that sapiens waited 190,000 years before coming up with civilization? It's not weird, because it didn't happen. There have been several global high-tech civilizations. The remains of which were wiped out when the ice age came. 

 There were in fact numerous varieties of sapiens-tier homo before the ice age, but all of them except the africans and one other were wiped out, mildly by climate and mainly by infighting and sudden black government collapses. (Global warmists dimly recall getting massacred by glaciers. Ancestral memory. Then get confused because ice ninja instead of tropical ninja.) Neanderthal was always polar homo and simply expanded south. ("More for us.") Africans are not native to africa, they are colonists from some ice-buried zone. They are degenerate because the pre-ice civilization had a black, china-style government. Black government causes ninjaification. 

 Colonial america farmed by exhausting the farmland, then clearing more so as to exhaust that too. This sort of behaviour is what leads to dust bowls. Indeed americans still behave this way if they can at all get away with it, such as the recent AI craze having polluted the AI-training well. Likewise, all black governments function by exhausting their host race, then attempting to move onto the next one. Which is a problem when there is no next one. 

 The ninjaified race does not recover. Against almost any kind of environmental challenge, it doesn't adapt, it just dies. It is soft. It can only survive on life support. Can only walk with crutches. If it isn't easy, the remnant race can't do it. See also: political or war challenge. There used to be a tiny elite that maintained civilizational life support for the slave base, but statistically they didn't make it; with a global ice age, there was nowhere to run, nowhere to defect to. Quite possibly they weren't even sapiens, but some of kind of elf slavemaster. They, too, required supports to live, in the end. They needed their slaves, but couldn't retain control of them in the chaos. Whoops.

  None of them could survive in the wild. (In modern times, you may be able to bring to mind an example of this. One or two.) Thus [out of africa] - the one place sapiens didn't wipe itself out.

 Rather than recovering the ninjaified race hybridized with barbarian neanderthal, revitalizing the genome to some degree. Enough to get tax-farmed back down to uselessness, anyway.