Some airports in the US have long cab lines. Las Vegas and JFK come to mind. In Las Vegas the line exists simply because so many people fly in and need cabs that the capacity to fill them is the constraint. The same is true at JFK. Turns out Newark, NJ (EWR) also has a cab line but for a different reason.
In Las Vegas, the goal of the cab dispatcher is to get people into cabs as fast as possible so visitors are not frustrated by the wait and to get visitors to their hotels so they can start stimulating the Vegas economy. In JFK I’m not sure the goal is to minimize frustration, but they do seem focused on getting people into cabs.
At EWR, the goal of the dispatchers seems to be to prove they are in charge. Their process slows down the cab line, frustrating both the cab drivers and the passengers, but does assure that the dispatcher is in charge.
Every process is perfectly constructed to produce the results it does. If you are not getting the results you want from your process, we recommend you look at the process first, not the people. Though at EWR and the cab dispatch process, we may have found an exception to the rule.