I wouldn't say it was a good career anymore but, despite the fact there can be a significant pay difference between the Airlines and GA, if your son can get into a GA organisation then he may well prosper in time. The thing to remember is not to become "fixated" with the Airlines as a career. There are plenty of other engineering requirements for the many and varied means of aviation that exist.
Despite the fact he would be doing an aircraft engineering course, he should still learn the basics of engineering per se and thus have a reasonable grounding for other avenues if he wishes and is still young enough of course----and if he has any sense--and this from an A & C person----he will get into the Avionics world rather than the mechanical.
I suppose it all depends on what other prospective careers he has / will look at after all, but I don't think he would do too badly in GA / Biz or the Helo world overall.