It seems like you're choosing to selectively interpret things to fit your own argument.
> Meanwhile, societies like USSR and Communist China, that persecuted their geniuses, collapsed their previously great societies.
They did indeed kill off most of their intelligentsia in the last century. This is clearly what the OP is referencing and is a historical fact. I'm not sure why you decided to take it in a different direction.
Because for neither China nor the USSR was that the main contributor to their national problems. Further, the education system of both are definitely implementations of "let's spend the most money on the smartest people".
In a discussion about the collapse of societies, it doesn't apply. In a discussion about education reform, it does not apply. It is also not an example of the original commentors statement that conquerors have used social spending to collapse their targets.
I would further point out in both the case of the USSR and China's purge of the intelligentsia; it was FAR more about consolidating power in a dictator and far less about trying to set good national policy. In Mao's case in particular, he was frankly just a bit insane.
There’s a selection bias in that the USSR and China both actually turned into barely functioning societies afterwards, often because they implemented their ideals in inconsistent or hypocritical ways. If you take the same ideology and actually apply it consistently you’re the Khmer Rouge.
Sounds similar to religions. If a religious group sticks strongly to its religion's founding principles and teachings, it's "fundamentalist" and is basically a cult or something like The Handmaid's Tale. The groups that water everything down and are hypocritical and inconsistent are much more successful long-term, with far more members and lots of money.
The main difference is that unlike Marxism, most traditional religions can be the basis of a long-term successful society even if you apply their ideas consistently.