Well, yes and no.
I agree with the point that the careers, if too many are mashed together, become uncomfortably similar to classes in D&D. And it's not so much the limiting of options we're for here - it's having ENOUGH careers that the fact an individual career only has so many exits is outweighed by the individuality of the career paths.
Remember, if you want to switch career paths you can move to a new basic career. OK, so it'll be slower to get better at the new job - but isn't that a reasonable approximation of a real-life adult switching careers? They're going to need to do some scut work before they become an important figure