It can be summarised as tunnel vision. They see what they don't wanna see through anime and jrpgs and fail to understand that these forms of entertainment are just that... Entertainment.

This can be applied to most things as well, not just Japan. Take a look at any roleplay and someone will either have Nippon Steel, a family massacre, or some abilities that make no sense for the character. Rather than writing an engaging story they'd much rather write a self indulging experience.

(That's not to say all tropes are negative. It depends on the RP.)