There is a certain element of truth to what you are saying. When I was early in my training I was dissappointed in my choice of medicine as a career because I also thought it lacked an outlet for creativity. As a now experienced physician, there are still times when you get to a point in the care of some patients at which the next step is programmatic and rote (if A then B).
However, sometimes--probably most of the time--the patient's presentation is so unclear (e.g. "I just feel weird. . . ."), there are so many variables to juggle in your head at once (twenty different lab values, the way the liver feels, the imaging findings, the color of the patient's sclera, the smell of their breath, their mood) that things become far too complex for any flowchart. These are the times when you need creativity, "book smarts" and perhaps above all, "emotional intelligence" to be a good doctor. There are plenty of doctors lacking one or more of these elements, and they just aren't very good at the job.
However, sometimes--probably most of the time--the patient's presentation is so unclear (e.g. "I just feel weird. . . ."), there are so many variables to juggle in your head at once (twenty different lab values, the way the liver feels, the imaging findings, the color of the patient's sclera, the smell of their breath, their mood) that things become far too complex for any flowchart. These are the times when you need creativity, "book smarts" and perhaps above all, "emotional intelligence" to be a good doctor. There are plenty of doctors lacking one or more of these elements, and they just aren't very good at the job.