Isn't that basically Cloud's Mastermind: Strategist for Hire in a nutshell?

Fuckups leave dangling threads for fic writers to weave into something new and beautiful.

Another example: Marvel. I'm Civil War Team Iron Man, Loki was never a villain only an antagonist, Wanda was the token evil teammate, Vision was a downgrade, Foggy was under-appreciated, Sylvie was obnoxious, and Cap had no brain. Excellent grounds for fanfic.

Basically, fanfiction is a popular recourse when a media property is GOOD but also FLAWED AF.