Most decisions on what medications wind up on the formulary, or what devices get purchased, are made by administrators who aren't taking care of patients. The problem is that they tend to make purchases entirely on what is cheapest, and that is sometimes not the best thing for patients.
I'm not saying that there aren't bad unethical doctors, but I assure you that the vast majority are not.
Once my pediatrician asked my kid about guns in our house, without us around, that was the end of my confidence in them. They OBVIOUSLY have their own agenda.