I currently run a large high-end retail store in an outdoor mall. Although plenty of other businesses around my store have restrooms, they do not allow their patrons to use their facilities. In fact, they take it a step further by suggesting that they come to my store. They even tell them what area in the store to find the restrooms, so that they can hurry in and return back to their stores... The businessman in me knows that these customers walking through my door are added traffic and an opportunity to sell them something. The flip-side to this is the majority of the "customers" visiting my store just to use the restroom come from one of two stores: A pre-teen clothing store, whose customers are young girls who are dropped off by their parents to shop, and a big-chain bargain-reseller whose customers are not interested in much that is high-end--unless it's last season's. My company does not have, nor will it allow me to implement, a patrons-only policy. At the same time, my company has devoted much time and money into tracking the conversion of our traffic to transactions. As a general manager, I am accountable for a metric requiring us to sell to a certain percentage of our traffic. It is, in part, how my performance as a manager is measured. The plumbing in the surrounding area was installed many, many decades ago. As such, even the slightest plumbing issue results in about a $1000 plumbing bill every time I call. These funds come out of my operating-expenses budget and are a direct measure of another metric, profitability. So, say half a dozen 11-year-old girls are dropped off next door. One has to go to the bathroom. Well they're girls right? Then they ALL have to go. How many 11-year-olds do you think know better than to throw paper towels in the toilet? Not as many as you'd think. So, should business have the right to not offer you a service? Damn right? Should basic sanitation and public health be maintained? Of course, but maybe they be provided by the mall, or strip mall that these businesses occupy. As a side note, here in the golden state, I think any "restaurant" is required to offer restrooms to their patrons by law. Sorry Starbucks, you're screwed...
However, I think that any place that serves food should have a restroom. My problem with Starbucks in this case is that they serve food. At the very least, I want to wash my hands before I eat my scone. Also, coffee makes you need to pee. Much of the attraction to a coffee shop is sipping you coffee as you read, work on your laptop, or talk to a friend. I'm sure that in a perfect world for Starbucks, everyone would get their coffee and leave, but that's not the business they are in. They are in the food and drink business. Restrooms are part of the package.
My wife and I recently flew Spirit Airlines for the last time. The ticket was cheaper, but it cost us $40 each way for the one carry on bag we had. If you are an airline, people have luggage. Businesses that fuck with a customer for using their services in a rational manner get no sympathy from me.