A thing done intentionally is not a mistake.
It is if the intention is to do that which one has neither the right nor the ability to do, then intending to do it is a mistake. And seeing how most ‘Americanisms’ (a much better term than ‘american english’, seeing how the differences are minimal and Americans speak regular English – or try to – in virtually every respect) are borne from Hollywood or corruptions over time, I think mistake is not too strong a word.
FYI you forced english on US, just like the Spanish forced spanish on Latin America and Portugal Forced on Brazil and the French forced french on their former colonies
And?
We still invented it, developed it and are, right now, by far the best at using it. You still call a sport involving very little foot action ‘football’. And no-ones answered that one yet.