This makes me wonder if on some level, some mental health professionals don't actually believe in mental health problems.

Although, perhaps, what they were clumsily trying to get at isn't so much a doctor being annoyed at a cancer patient for having cancer, but a doctor being annoyed at a cancer patient who smokes five packs of cigarettes per day.

Unfortunately, mentally unhealthy people make poor self care decisions a lot (I don't know about you, OP) just generalizing. I can see how that would be frustrating for professionals, then again, that's why they get paid huge sums of money.