If anyone’s going to get a fine there it would really be the individuals. While the business is creating the demand, there isn’t really any process they could put in place to stop people lining out onto the road.
Also, if we were going to forbid it, what would be the substantive difference with forbidding just parking on the public road? Which, yeah, that’s definitely a conversation we should have and a direction we should move towards—it’d probably have a greater effect anyway. But it’s not clear that there’s really a great mechanism for specifically banning queueing.