For example, it's likely that much of the scholarship of western antiquity was lost in the closely spaced sacks of Constantinople and Baghdad. The Mongol destruction was particularly thorough in their destruction of scholarship: "The books from Baghdad’s libraries were thrown into the Tigris River in such quantities that the river ran black with the ink from the books."[1]
Plus, geographical context arguably played in Europe's favor for the latter: cut some trees and start planting likely yields more individualistic and competitive values (small kingsoms) than flood plains that require intense cooperation and submission to the greater good of society (large empires).
The mongols put in place the Ilkhanate and sientific and cultural work flurished for a time.
In Islamic memory the sack of Bagdad is legendary and it has been put as the explenation for the decline of islamic civilisation. I would be very hesetant of using "lostislamichistory" as a source.
Some of the same arguments could be made for china and the romans (eastern).
Why did the Mongols hate books so much? Central Asian Turkic invaders (related to the Mongols) were also responsible for burning down one of India largest libraries (at Nalanda).
I don't understand why certain groups of people would be so bent on destruction. Destruction of life, property, art, culture, scholarship, literature, etc.
It is very sad.
Mongols did not consider the people they conquered to be far above cattle. When they took over cities they staged systematic executions where they would literally corral a hundred thousand people together, and have a thousand of their soldiers armed with axes be told "go collect 100 right ears to prove that you've killed your quota of people". As far as I can tell the way to get humans to do that to other humans seems, throughout history, to be to convince the murderers that the people they're killing aren't really human, they're just some sort of weaker other-species.
http://www.dancarlin.com/product-tag/mongols/ (free at the moment apparently, good listen)