It’s why Chicagoans call it a “pie,” Justice Scalia. Nonetheless, I trust your judgment.
The funny thing is, Chicagoans don’t call this style “deep dish” (it’s called “stuffed”), and it’s not the most common kind of pizza we eat. Mostly, we eat Chicago style thin crust, which is different than New York style but very much a traditional pizza. I think the stuffed is just so distinctive, it’s what the rest of the country thinks of as “Chicago style pizza”.