What you're forgetting is it absolutely would not work when you first put it together. You would then begin a journey of debugging which would teach you a lot more than any YouTube video ever could.
Just to give a little context as a pilot: It is the job of the tower controller to decide who uses the runway when. There are often multiple planes waiting to take off, and multiple planes nearing the airport to land. It's not uncommon for a tower controller to allow a plane to takeoff while another is approaching the runway. The theory is, of course, that the flight will depart in plenty of time.
In this case, the controller failed to tell the departing flight to hurry (the references to 'no delay' or 'immediate' in the blog post), AND frankly timed things pretty close given the weather. Without the ability to actually see the approaching plane, or perhaps even the plane on the ground, it will probably be found that timing a departure that close at all was reckless. That said, I feel for these tower controllers, it's not common for many planes to get stacked up waiting to depart, and it is their job to get them out. What may have worked just fine on a clear-weather day simply became too dangerous on that day.
The official manual for air traffic controllers in the US is the FAA Order JO 7110.65W [1], if anyone cares to review it.