First, why does it matter?
Second, no one on this forum was alive when the game was invented, therefore, I'm sure that none of us had anything to do with naming the game, football.
Third, soccer was referred to as association football and rugby was referred to as rugby football. American football was derived from a combination of the two, so what's wrong with simply calling it football? It's not rugby and it's not soccer, so it would have been wrong to call it either of those names.
Fourth, why am I even replying to this post?