That may be true; in the mind of the surgeon. But, VERY FEW surgeons truly does this for purely altruistic reasons. If people honestly believe that ALL do, they're dreaming or in denial.
However, I believe that it's too much of a sweeping generality to say that ALL ENTS that implant are greedy and in it for the money. But, most are. That's just our society and how we operate (pun not intended). Nearly everything is driven by the almighty dollar.
Surgeons don't become surgeons because they want to work for free and make no money, even if their motives are altruistic in nature. Surgeons like everyone else need to survive. They need to pay the light bill, buy food, etc.. like all the rest of us.