I am in the same boat with my young son. Its a tough nut to crack the airline game, however there will always be a demand for the right kind of young individuals who are driven to make it their career. I wish that I had made the contacts as a youngster around my local airfield, washing aircraft, making the tea, anything. ATC is fantastic, oh how I wish that I had pulled my finger out as a young man and stuck with it. Who knows where I would be now. We as parents should stand behind our offsprings dreams and nurture them. My head says don't do it son, I am as cynical as anyone else about the airline business.
There will always be a need, help him become one of the Captains of the future.