The customer who sits half a day in a Starbucks is doing free advertising for Starbucks. A filled and busy shop attracts much more business than an empty one.
On the other side, starbucks don't need that type of advertising now and a small\upcoming shop can't afford that kind of advertising.
This idea is also business specific. Can restaurants afford whole day sitting customers? No, I think
"You walk into a retail store, whatever it is, and if there's a sense of entertainment and excitement and electricity, you wanna be there."
“We’re not in the coffee business — we’re in the experience business”