you should also tackle the English (and, in fairness, French) habit of answering a question, like, say "Who wants a cookie?" with "Me!". It's just as ungrammatical, but I've never heard anyone say otherwise in either English or French, so I rather doubt you'd get as much agreement if you tried correcting that one.

Another case of the same thing, again both in English and French, is to use "me" instead of "I" as a predicate ("It's me.", though there in English at least I have heard the alternative, even if it sounds old-fashioned now.