I think Mayday is correct; flying for BA, irrespective of whether you make it all the way to the top or not, is a highly rewarding career.
But I don't really think money is the primary driving force behind most aspiring pilots. Certainly I can speak for myself when I say that I want to fly because I have a passion for it. If my career was only about money then I'd make far more of it, far more easily, by going into business. People who are mostly driven by money go into business - not aviation.