Doctors have a duty to ease suffering and alleviate pain. Whats better: a coherent, terminally-ill patient asking their doctor for medication to assist them in their self-administered suicide (as I understand it, the doctors prescribe the meds and show them how to do it but do not actually administer the lethal dose) or a dying patient lying incoherently in a morphine-induced pool of hallucinations and their own bodily wastes?
I'd rather see the former than the latter. I've seen enough of that to last a lifetime.