Many medical practices (and other businesses) are poorly operated and administered. I think of my dentist: terrible website (even by 1995 standards), awful at follow up, weird insurance coverage (since she doesn't have time to follow up with new plans it seems) and almost no appointment reminders. There are obvious things to do that could drive business for her.
It makes sense to me that someone could come in and say "hey, let me run the business + finance side of the house while you practice medicine" and at least on paper I can see a real world where that works out for everybody.
Of course, soon you end up with dentists pushing unnecessary procedures and more, so it doesn't always works out that way.