This is an American interpretation. Here in the US, cones, lights, or lane-blockers are used to close exits.
Culturally, its because American's won't read a sign and follow the instructions if we can still "do" it. You have to physically block us, and its too expensive to change all the signs.
Culturally, its because American's won't read a sign and follow the instructions if we can still "do" it. You have to physically block us, and its too expensive to change all the signs.