Is that not the format that's actually used in the US? I mean, it's utterly insane, but a lot of people really are used to having the components of the date in random order.
In what way is the MDY you write about any different from the YDM in the screenshot? The important thing, that they're in random order, is the same for both, right?
And as for spoken language, it's not like any normal person would say "September fifteenth" now, is it?
Turns out people in different countries and regions say the date differently as well. I find it funny how everyone always assumes their experience is the universal one.
September Fifteenth and Fifteenth of September are both commonly used depending where you are in the world.