This article is light on the details of the failures, but basically the little bits of lettuce, tomato and cheese would slip out of the various holders and get smashed into the moving pieces and jam everything up while starting to rot. It was broken more often than not, and even when it wasn’t it was a pain in the ass to keep sanitary. Far more trouble than it was ever worth.
Building these machines and operating them won’t be the hard part. Keeping them working will be more expensive than paying people to make food for a halfway decent wage. The necessary logistics system just to supply replacement parts for the machines will probably break the bank, and never mind all the technicians they’ll need to make repairs.
It’s less a function of not having decent Mexican food and more a function of both food trucks and the concept of “walking distance” not really being things in most of the metro area.
We have bodegas and trucks, for a very reasonable price, although the trucks cost less, I suppose because of less overhead. If anyone's never had homemade tortillas, I recommend them. In the bodegas, they usually have a machine, similar to the wringer on the antique wringer washers so they're thin and more uniform, but hand made masa tortillas are divine, especially topped with avocado and queso fresco.
I wish I liked QDoba, Chipotle is still better to me even after all their changes which I am not crazy about either. Luckily we have a local chain that beats the pants off them both called Illegal Pete’s