There is nothing wrong with wanting to be a professional pilot, but as people have pointed out, it’s not without it’s issues, particularly the debt incurred. If the boy just wants to fly, then it might be worth just doing the PPL and flying for fun. Flying when he wants to and not when he has to. Flying when the weather is nice and not miserable. He’ll still be a pilot and no one will think less of him because he doesn’t fly large jets.
Even with a PPL, you can achieve quite a bit when you have instrument and multi engine ratings.
As he is already going down the PPL route, I would recommend an intensive course, somewhere the weather is nice. I went to Texas to learn and did the course in three weeks. It would have taken months in the UK and was significantly cheaper. Of course, I still had lots to learn, but once I had the licence, I could Fly at my convenience and not have to rely on others to build hours.
I will say he is lucky to have a father so interested in his career and is prepared to solicit advice on his behalf. I hope it works out for him, whatever route he takes.