It's not the defence many Americans seem to think it is of their insane method of writing the short form.

I've never once been confused about a written date whilst in the US. Your country's other-side-of-the-Earth flip-floppery on how it uses dates really doesn't (and shouldn't) impact our system, which we continue to use because it has proven effective and easy. Trying to stagnate an evolving culture/language is pointless and about as futile as trying to force a river to run backwards. If people start jumbling up how we do it here, like you say Australia does, then that will be right, too.