Yes, and also many fandoms lack the maturity to know when to say "no, I do not want to know MORE details, and certainly not about this obscure secondary character's difficult childhood that explains everything they did later in life".

See:

- All of Wookiepedia and most of Star Wars Expanded Universe.

- "The Hunt for Gollum".

- Every movie in the franchise after "Alien" and "Aliens".

- The sadly upcoming expanded universe/sequels/shows for Blade Runner.

Etc, etc. Everyone has their exceptions ("this one was cool"), but in general the point stands: fandoms ruin everything. They simply don't believe in the adage that "less is more". They always want MORE, and the industry is only happy to oblige.