Dinner normally runs from 6-8. In those 2 hours the bulk of the customers hare handled. The more turns you get for those hours the moe money made. If you show up at say 8, then yes staying longer will add to bottom line. If you arrive at 6, they make more money if you leave fast.
Back in the good old days, before people like you and your buddies were actually taken seriously, there were plenty of restaurants who catered to smokers during those hours.
Any statistics on how they're doing now?
You know, the ones who are patronized now by people with coupons who order pasta dishes, or the real risk takers who might get the boiled chicken and linger over endless cups of coffee, bumping the check up another buck?