One word: Ambiguity. We need to either have a standard and stick to it, or a small handful of standards that cannot be confused for each other. DD/MM/YYYY and MM/DD/YYYY can be confused for each other, so the nonsensical MM/DD/YYYY should move over and make room for DD/MM/YYYY, or we should drop both and just use YYYY-MM-DD.
I like that this can be interpreted as implying that Heracles is a Disney villain.