I did my PPL because I love flying, and my BEng degree because I wanted to work as an aeronautical engineer. Both worked out fine.
I did my PhD simply because I wanted one, and my CPL mostly for the benefit of my ego. As it turns out, both have massively benefitted my career - which wasn't the objective. Put those together, and you get somebody managing aviation research - which is mostly me at the moment.
Possibly I have done relatively well because I just keep adding "stuff I can do", and make my only real absolute that I want to stay in aviation.
I can think of a former PhD student of mine, who did a good aeronautical engineering PhD, but is determined "only" to go for the straight academic career path. In that, he's been very unsuccessful.
I can certainly think of people who "only" wanted to be airline pilots, and have failed miserably.
I flew with somebody the other day who went PPL -->ambulance driver --> CPL --> instructor --> ambulance technician --> air ambulance pilot. He seemed to have had an erratic career, but a lot of fun, and very little time unemployed.
Maybe flexibility is the key - the more open minded you are about the stuff you're prepared to do with your skills and qualifications, and the more prepared you are to add to those without being too narrow minded, maybe the better chances of doing things you will enjoy (and pay the bills!)
G