Addressing your secondary point about judging a book by its realism...some people's enjoyment of fiction depends on how believable the plot is and if the character's choices are at least justified by the rest of the story/characterisation/character development. People's thresholds are different. And when a plot/character choice and action is too way out there it just takes them out of the book; prevents the proper suspension of disbelief.

So it's not so much about enjoyment vs education, but rather how strictly plot and character development needs to justify the events in the story.