I don't think any system will be able to cope with the horrible final effects of motor neurone disease and the only way to deal with some agonising terminal illnesses seems to be to keep one permanently sedated, so the patient might as well be dead.
We are not talking about killing, but simply making it possible for people to die at the time and place of their own choice. At the moment, people are having to go to Switzerland before it is necessary, so that they are still able to travel under their own steam. Why should they not be allowed to die in their own home, with all their family around them?
The law in the UK is a complete fudge, with the DPP saying assisting someone to bring about their own death is still illegal but they are unlikely to prosecute. What is the point of that? Patients need to know that they are not putting their families and friends at risk of prosecution.
Even the catholic church admits 'Thou must not kill, but need not strive, officiously to keep alive' - i.e. withdrawing artifcial life support systems is allowable as it is natural.
Doctors are trained to preserve life and often react badly to the death of a patient. My mother's last few years of life were a nightmare for her and my brother and sister who were caring for her. She was not in any physical pain, but in a constant state of anxiety because she did not know who she was or what was happening to her. She developed pneumonia at 90, and the doctor told my brother 'With god's help we have been able to save your mother'. For what? Another few months of wrenching anxiety. No thanks.