You would never operate any flying sector with only one pilot on a commercial airline. But airports do operate with one controller. What happens if something goes wrong. I think owing to commercial pressures Airport Management are willing to take the risk of working one controller on a night shift. Due to the increasing shortage of ATCO's and the unwilling attitude of airport management to employ extra controllers then one person manning will happen more often. If you read the Notams which say "radar may not be available" then you will see which airports are doing this. I know for certain that Leeds and Teeside sometimes operate with one ATCO only during the night.
Please prove me wrong.