Just come to me when you feel bad, and I'll cure you. Division of labor, you know. It applies to organizing a factory. To some extent, specialization applies to what you do to qualify yourself for your career. Maybe, in some respects, it pays off to be a generalist.
Doctors depend for their livelihood on people being unhealthy.
If everyone were perfectly healthy, most doctors would be out of a job. It's in the interest of doctors that people generally suffer poor health. It's in the doctor's interest that his clients be ignorant concerning what they need to do to maximize their health. The same applies to many lawyers. The more ignorant the client, the more money the lawyer can make.