Goals in Therapy?

There's something about psychiatry, as compared with general medicine, that I have never understood.  I am baffled by it.

Psychiatrists always ask the patient, "What are your goals in therapy?"  In general medicine, physicians never ask that question.  Physicians will diagnose an illness and recommend a treatment or various treatment options.  In general medicine a doctor does not say to a patient, "You have gallstones.  Now, what's your goal?"  "You have colon cancer, what's your goal?"  It is the doctor who recommends the goal.  And in the case of a life-threatening illness, the goal is to save the patient's life or prolong it or palliate the patient's suffering.

I have a schizoid personality disorder.  The essential symptoms are massive splitting and isolative defenses, severe identity disturbance, and an identification with the anti-libidinal object.  I would hope that my psychiatrist would recognize that, understand it, and know how to help me moderate those symptoms.  Other than that, I have no goals.