I've heard this argument before. But, if you combine this with something BBI said earlier, about God revealing Himself through Mohammad in a manner that acknowledges that revelation changes (I'm paraphrasing here) to facilitate the current understanding and sociopolitical landscape (e.g. these are the commandments for times of peace, and these are the commandments for times of war, etc.), why would God only reveal Himself in a manner in which He is only fully understood in one, specific language? Is God okay with not being fully understood (and therefore, not fully accepted) by those who are not literate in Arabic? Does God expect the whole world to become literate in Arabic? I'm not sure I'm comfortable with the implications of either.
I think the same argument could be made for people's, past and present, who've never heard the word of god, I've heard a lot of different explanations for how God reaches them and they all include some form of they're being godly people despite having not read the bible. I'd think it would make someone just as uncomfortable, it does me, to think God only reveals himself I his true form to a select group of people with access to the bible in their language.