This is a strange argument to make against "octopuses". Break from our history; use the English standard; we are not speaking Latin ... therefore it should be octopi!? What? How about this: it's OK to use the traditional form if it's still commonly understood, but otherwise let's try to use a "standard English" form. Those are your choices: traditional for the word, or standard. Since "octopodes" is awkward and not really ever used, we say "octopuses". Why would you convert to a false-traditional version?
