This is some scary ***** that is being exposed. One must ask, "Who's watching the store here?"
All this is not new, and it's not that scary. It's media sensationalism.
About 95% of the airports we land at, have no control tower, or they have a tower that closes at night. They need controllers at some airports when it's busy during the day and early evening. (Notice controllers never fall asleep during the day, it's because they have something to do). At night, it is the most boring thing you can imagine, sitting there, sometimes for hours, in the dark, by yourself, with absolutely nothing to do.
This is not the same as the city worker, or postal employee sleeping in their car, to to avoid work. When controllers that have no traffic, they have nothing to do.
Controllers have always fallen asleep, (if you know one, ask them), you just did not hear about it as much. Normally they set the radio's up to full volume, so if they do doze off, they wake up when they get a call.
Possibly the average age of controllers has gotten higher, so they are more susceptible to sleep now. Rotating shifts are a big factor.
The fact is, if there is so little to do, they should not have a controller there, they should close the tower. Another option is to move the approach controller for that area, into the tower at night.
It's not a big safety issue, you can see other aircraft at night very easily, and except in some places, their aren't very many. The approach controllers still have the aircraft on radar when they can't reach the tower. So, the approach controller is also able keep aircraft apart. The tower is there simply to separate aircraft on the runways. If there aren't any other aircraft, there is no issue. When you fly into an "uncontrolled" airport, aircraft can call out where they are on the radio, to help keep everyone aware of their position.
The over hyped loss of separation incident with the first lady, resulted in 2 aircraft getting within 3 miles of each other, hardly a near miss. It shouldn't happen, but it does. Loss of separation pretty much happens somewhere in the US everyday. Only a small percentage are serious. The number of incidents have been steadily declining each year, as technology finds ways to prevent them.
Everyone agrees this stuff should not happen, but the system is the problem, not the people. Perhaps now this part of the system will finally get changed, and the fear mongering can stop.