I'll bet you're not a chocoholic either; you don't fly a quadcopter; you've never entered a hackathon or danceathon; never complained about stagflation, tipflation, greedflation, or bridezillas; and you don't own a Goldendoodle.
(These, and "chicken burger", are all examples of linguistic rebracketing.)
The word burger has been separated from its origins in Hamburg.
In modern use, a hamburger is a beef patty, and a burger is any meat patty. Deal wit it
The real question is...what should we call a burger made from ground ham?
While traveling in Spain many years ago...and completely desperate for a good old fashioned American cheeseburger, I spotted a street vendor selling 'hamburgers'...and in my haste and desperation, ordered two. You cannot possibly know the misery that came over me as I realized half-way into my first bite that it was ground ham.