As a few of the previous posters mentioned it is a really horrible time to be a commercial pilot. However, only a month ago it was one of the best periods in history to be a pilot. Things change in this industry extremely rapidly, and it will likely take several more years before it improves. That is good and bad for your son. Even if he started his training tomorrow it would most likely take a few years for him to get enough hours to get hired by a regional so maybe it will be a good time to be a pilot again then.
I would also echo the recomendation to get a degree that is useful, and also get the military to pay for your training. The pros to the military are huge and as a prior Army Blackhawk pilot I can say without question that it was one of, if not the best decisions of my adult life to join the service. In addition to learning to fly helicopters, getting to serve with outstanding individuals, and to serve overseas, when I completed my eight year tour I earned the GI Bill. After getting out, I went back to school using the GI Bill and got my fixed wing ratings. I flew for a regional for about a year and decided that wasn't for me. Now I'm flying a Lear Jet as a Medevac pilot in Alaska. All of that aviation training with no six figure debt to pay down.
The military route isn't for everyone though, and all aviation training demands a very self disciplined individual with particular aptitudes and physical requirements. Given all that, I personally wouldn't recommend becoming a pilot.
Think about this for quote a chief pilot told me once I earned my private pilot license. He told me, "congratulations, welcome to the lonely, poor pilot's club."