Were China and Japan really as peaceful as is sometimes stated? Just looking at a timeline of Chinese historical events (and probably by no means exhaustive) I see rebellions and invasions and peasant army uprisings for thousands of years:
https://en.wikipedia.org/wiki/Timeline_of_Chinese_history
Not peaceful, but stable and unified. Relatively. Consider that there has been something resembling a Chinese identity for several thousand years. Whereas Europe hasn’t been unified since the fall of the Roman Empire ~1600 years ago. And even then, the parts of Europe that played host to the scientific revolution were barely part of the Roman Empire. Or consider the fact that, relatively recently, the Japanese decided to cut off all contact with the outside world and forgo technological development. The idea of a European power trying to do similar is basically unthinkable due to the fact that they would have had half a dozen other nearby polities where no such restrictions were in place and change would have simply leaked in.