Believe it or not, air traffic controllers don’t issue radar vectors for amusement. I know it might seem like it when you’re getting strung out for a sequence or for traffic, watching the time-equals-money clock ticking away, increasing the costs of your flight.
My goal as a controller is to get you on your own navigation as soon as possible— the less I vector you, the less work I have to do. The obstacle to turning you loose is that there might be traffic conflicts that require me to comply with internal traffic-flow procedures.
