I'm surprised nobody here has connected this with the recent controversy about the purchase of the new Dutch government plane.
The old plane (a Fokker 70, occasionally piloted by the king) is mostly used to fly members of government around, but is getting old, hard to maintain, and the range is too short to fly non-stop to many countries, which is obviously a rather important role for the plane. So the government needs a new plane with better range. The Airbus ACJ319 is a perfect fit, and 15 million cheaper and more modern than a Boeing 737. The government has still decided to buy a 737 instead, because the king was already training to fly a 737.
I was wondering why he didn't simply switch to training for the Airbus, but apparently this is the reason. I suspect KLM has plenty of 737s for him to fly, and not the right model Airbus. So the government is basically paying 15 million extra to support the king's hobby.