I like some of these stories, and I think you're being a little unfair. The pattern of the child who turns out to be magic, or the loner who becomes a hero: these are archetypes that touch something deep in human beings. Sure there can be an egotistical - I'm using a less vivid word than yours :) - element to how we identify with heroes. But I think on a deeper level, it is a universal experience and not an egotistical one.
Take for example The Matrix - I really liked that movie when it came out, and part of what I enjoyed was the story of Neo turning out to be The One, and I certainly identified with that character. But so did everybody else who enjoyed the movie. If it were pure egotism, the enjoyment wouldn't be shared. Instead, you'd get arguments like "I'm Neo!" -- "No you're not, I am!" That doesn't happen with the best of these stories.
Take for example The Matrix - I really liked that movie when it came out, and part of what I enjoyed was the story of Neo turning out to be The One, and I certainly identified with that character. But so did everybody else who enjoyed the movie. If it were pure egotism, the enjoyment wouldn't be shared. Instead, you'd get arguments like "I'm Neo!" -- "No you're not, I am!" That doesn't happen with the best of these stories.