as far as I know it was a simple mistake
and it's the entire point
if you can transpose a movie to a different milieu without losing the narrative arc, then it's not a movie about the milieu
put Star Wars/ANH on a pirate ship and you don't lose much - thus is sci-fantasy and not sci-fi
Twilight is just YA romance - that vampires and werewolves are not germane - just pick any rival gangs
aside from Terence Mann laying down the overarching philosophy, FoD is a family drama
and what lessons we learn are about watching the sport not playing it
it's a great movie but it shouldn't be rated over movies that are actually about the athletic competitions of those particular sports