Aren't most lines created deliberately for security reasons? Like: crowd control, maximum number of visitors, metal detectors, luggage checks, etc.
I can imagine that some clubs deliberately create lines outside to give the impression of popularity and exclusivity. But for any other situation it is of economic interest to the owner to keep lines as short as possible (visitors can't spend money while in the line).
What I'm trying to get to is: I don't get why any event organiser or bar owner would want this.