Ditchdigger,
Your comparisons about what your kids did is not valid. I notice you did not let your son operate excavating machinery at full power on a busy building site, or let your daughter drive the dump truck on a public road in the rush hour.
Your comment about managing the risk is not valid either - the risk should not have been there in the first place.
To those who think this was just a harmless bit of fun, can I ask where in fact you would draw the line? Would it be OK for the controller to have had a family day in atc and let the boy's brother switch the airfield lighting panel, while the sister is in radar handing off traffic to tower, with maybe the wife inputting data into the flight planning computer. All under strict supervision of course!
Having said that, suspension or revocation of licence does seem a bit harsh in this case. A public reading of the riot act would probably be more appropriate, followed by formal written instructions in the US equivalent of MATS Pt 1 and CAP413.