It comes from a cursory understanding of the world outside of western countries. People watch a few videos on youtube about other countries, or visit on vacation for a week, and assume they understand the mentality of people who live there. It's hubris. Then they apply western moralities to other cultures, implicitly assuming their own western ideals are superior.

For example, pretty much everything kulahan wrote about Japan in the grandparent comment is completely made up. Good narrative, emotionally aligned, feels true, stated with complete confidence, but absolutely fictitious.

Or the common HN crowd of liberals conditioned to side with criminals.