Actually, I think very many people over the whole world don't realize that the term "soccer" was invented in England. I lived in England from 2008 until last year - when I politely pointed out that the term originated in England to those (i.e., many) who wanted to mock Americans for "making up" the term, they were genuinely surprised to hear that it was a native word. (The other major misconception is that the term is only used in America - also wrong. Many countries use the term, especially those which are part of the British Commonwealth - thus, revealing that those countries merely borrowed the term in use in the mother country.) It was used interchangeably with football in the UK until the 60s. We just use it because you used it originally, and we already had a sport called football.
Still, IMHO, soccer being called "football" makes more sense than American football being called "football", even more so since our football is ultimately derived from rugby...