I've been to the In-N-Out at Fisherman's Wharf when I lived in SF. It's obviously in a high volume tourist area with lots of foot traffic.
Many hamburger places, like junk-in-the-box, do almost 70 percent of their sales in drive thru. Can't imagine a drive thru being allowed in midtown but I think most residents will welcome a drive thru-less In-n-Out anywhere in midtown rather than another high priced steakhouse or even sushi restaurant.
Hamburger Patties and Jim-Denny's are sit down restaurants with pricey burgers mostly in the $7 to $10 range. Regardless of what Wburg thinks, midtown has a lot of young residents too, without huge disposable incomes, that want burgers at the reasonable prices a quick service Mickey D's or In-n-out provides.