Originally Posted by Mr. Wooden Alligator
Awe boy here it go.
Plausibility is the key word. If young Bruce had some psychological issues, saw his parents murdered and the cops doing nothing, its not hard to believe that he might try to do something.
Fear of losing what he has. He was only a child. His parents provided his rich upbringing. Then suddenly he's alone. He probably wouldn't know what to expect. His life could come crashing down around him. The injustice likely sickened him.
So what does he do?
Trains himself and decides to take things into his own hands. Hence he becomes Batman. That's plausible.
Mob gets tired of his **** and works together to get rid of him before resuming their petty disputes. Odds are they'd be successful.
Bottom line: Batman has some sort of "realistic" also totally exaggerated origin. But of course his actions are as unrealistic as it gets.
Superman has an unrealistic origin, but him fighting criminals is actually not that far fetched.