As I remember, Morse was the most-failed of all the CAA ATPL exams, and it's probably the one subject that has everyday usefulness in the air. I wonder if those two facts are related?
Knowing Morse is a basic airmanship requirement as long as the beacons you navigate by are identified by Morse code. You should see how often my steed, that wonder of French aviation technology, the A340, gets its Morse identifications wrong!