I am a bit perplexed on some of your hang ups with this field. Yes, it is a complex process to get a pilots license and fly for the airlines, but literally hundreds of thousands of pilots have done it over the years. Just ATP themselves turns out well over 1,000 pilots per year. The process is no more complex than being a lawyer and is actually easier and much shorter than becoming a medical doctor. Any kind of advanced education will have a lengthy process to it that requires time, dedication and money to accomplish.
The cost to reward equation is rather straight forward. Please check out apostle’s in the FAQ section that is all about pilot pay.
As for the degree, it is necessary if your son ever wants to fly for the major airlines. The payback in this industry is not in using your degree, it is in having a degree to get to the majors, which is where the money is.
Education costs money, but it has its rewards and they are quantifiable.
I would encourage your son to join the discussion on here.