Good article, I agree that you can't simply convert a special interest into a job.
When I was 9 years old I wanted to be a spaceman. It didn't look as if it would be too difficult - I was interested and intelligent enough to do the job, and technology was advancing in a way that made it look as if there would soon be lots of manned rockets going off to other planets - but I eventually realised that the world doesn't work like that.
I settled for a science research job. To some extent, I was a good fit. I was fascinated by science and I enjoyed a lot of the work, and my results were of a high standard. But I discovered that there was a lot more to the job than liking the subject and being good at it. Employers seem adept at turning a good job into a nightmare. I noticed that those who got promoted were almost completely removed from the laboratory and pushed into doing tons of admin work instead. Even on my modest level, I was rarely allowed to simply get on with my science work. And I hated the other stuff.