As a travelling nurse I saw that all too frequently and it is often a manifestation of our fragmented health care system: a person with diabetes often has multiple issues (heart, BP, cholesterol, kidney, etc...) and sees multiple physicians and/or is in and out of the hospital. And, every time she sees a physician she complains of something else and so he prescribes yet another pill...

Actually, the worst culprit were the hospitals: the patient would come out of there with new or changed meds that their family physician knew nothing about and would not have prescribed.

A big part of my job was coordinating all those different physicians and their treatments; The conversation went something like:
"Hey, Dr. X, I'm a nurse working with this patient: Dr Y (or hospital Y) prescribed this and this and this. Do want her taking this stuff?" The answer was almost always: "Hell No!".

My patients were fortunate to have a nurse who knew the conditions and the treatments.

Otherwise they would have to do that by themselves and most people either don't have the inclination or assume: "the doctor always knows what's right"...

Healthcare needs to be a partnership. People need to watch out for their own medical care just as they would their house when they have multiple contractors coming in and out of it... But, the typical patient just doesn't have the knowledge to challenge the physician. So that is why the best physicians welcome a knowledgeable patient who participates in his own health care and asks questions. It makes his job a lot easier and it makes your life a lot better and longer...

Most physicians WANT you to be healthy. But they know they can't do it alone. They do their best work when they have an interested, involved partner in your health -- not just a passive pill-taker... (And, if your physician wants you to be just a passive pill-taker, I would recommend finding another physician).