I think there’s some truth to the notion that they’ve done this in markets and stores where they are more likely to have a problem with homelessness and non-paying customers. I’ve seen first hand how much time and energy some Starbucks employees have to put in to waking people up who are sleeping in the store, cleaning themselves in the bathrooms, or trying to bring in a cart full of their belongings. Goes without saying (in my opinion) that it’s sad and a failing of society, but it also has to be a real problem for Starbucks.
Most businesses just take care of that with a security guard. I'd think an $84 billion company can afford a $25/hr guard at some of these locations. McDonalds has figured out how to deal with the issue without ripping out their interiors.