Plenty of coffee shops have built their business around providing a place that's comfortable to relax in: free Wi-Fi, power outlets, lots of comfortable seating

Plenty of coffee shops have built their business around providing a place that's comfortable to relax in: free Wi-Fi, power outlets, lots of comfortable seating. Sure, all else held equal, they'd prefer that people move through quickly, but they'd also prefer to charge triple the price. The reason they don't, and the reason they do provide for customers hanging around, is that it's a way of attracting business (and prevents loss of business to competitors who try this strategy). The parent comment's suggestion seems more in less in line with this general approach.