This really, really, is not true at all. Only people who aren't doctors tell themselves it's all about passion. If you remove the financial motivation you will have far less people going through the rigorous schooling and sacrifice of youth required to become a physician.
I would also argue that the vast majority of engineers became so because it was a "good job" not because they're fueled by some extraordinary passion.
I would also argue that the vast majority of engineers became so because it was a "good job" not because they're fueled by some extraordinary passion.