Agreed - the idea of checking in for a flight is antiquated. We get electronic BPs, so no need to queue up for the paper one. Maybe it's just telling the airline that you do intend to fly and maybe haven't made it through security yet... but then again, that doesn't really change the outcome because if you are late the flight leaves anyway. Maybe you can just scan your BP once you're airside to let them know that you're in the area, if they really want to know. They would definitely be aware if you've checked bags.