Because it's much easier to discourage than encourage people to enter the industry. Too many people lose sight of how it felt when they first joined and how excited and proud they felt.

Also if he catches this hiring wave right and does make the regional a career, it could work out pretty good. Yes not having a degree will stop him from the majors but if he so chooses there is still time to finish that.

If the airlines are really where you want to be and you and your family are financially secure (wife works, investments, savings, etc) then do what makes you happy. There are too many jaded A-holes out there that won't hesitate to try to smash your dreams because things didn't work out the way they wanted. Good luck to you.