You, as usual, have little understanding of the issue you speak about. Starbucks has for well over a decade marketing itself as the outside office or meeting place for professionals.
You do not need to have a drink or food items in front of you to sit there and network or work on your computer but AT SOME POINT, you should buy a drink or food if you are going to take time. But they have never suggested that point has to be the second you walk in there. Many a time I have met people in Starbucks after just having a coffee elsewhere, and not ordered anything. But as the meeting progressed over an hour or more I got up and got something. Starbucks knows that. The entire camp out and bring your laptop model knows that. They work on a 'sales per hour' model knowing on average how much someone will spend per hour seated. McD's opened lounges/cafe's to attract just that clientele.