Yes exactly that. Many also used to boast about how they did not have WiFi, although people's own cellphone connections are putting an end to that trend.
I have no idea, I've never actually been in any of those places, just noticed the signs walking by.
I know that establishments like this sometimes don't like people hanging around for too long without buying stuff, so it could be the reason that people would just get a coffee and stay all day. But this is just speculation on my part.