Isn’t “Philadelphia” a Non-English Word?

We’d read about this a couple of weeks ago, but it wasn’t until today that we saw this picture of a sign posted by one of those great patriotic heroes of freedom – Philly cheesesteak hawkers.

Maybe it’s our new-found empathy for linguistically-challenged foreigners, but if you’re scolding people for not using English, shouldn’t you be, like, using English properly? Or do those grammatically incorrect quotation marks around “Speak English” signal ironic intent? (“Just kidding! It’s fine to order in Flemish, if that’s what you prefer.”)

Or is this guy just “a dumbass”?