Dentists who focus on profit get bogged down in short-term, piecework thinking.
Dentists who focus on making a difference and solving problems for their patients will, in the long term, do just fine as far as profits are concerned, but will accomplish a great deal more for the community in which they practice.
Also, and this is the subtle part, the practices that focus on making a difference are robust and bullet-proof. Such practices create affinities; the profit-focused ones just deal in transactions.
I'd far rather create an affinity than merely perform a transaction.