I support your views on this, Termie. Some times the law is also a statement by the society at large about things which are important. Like human life. Legalizing some things and worse, turning them into some kind of absolute "human right", often has the opposite impact of making them not only 'legal' but normal, and then it becomes morally right in a lot of people's eyes. You also lose the ability to make compromise laws/solutions like the one you are talking about where not all cases are treated equally.
Now, as a person who closely witnessed my own father's horrendous suffering due to not just a degenerative illness but a few other serious complications for some years before he passed on, I understand more than I want to why people opt to do that. I still couldnt bring myself to do it (I don't think) but I can no longer pass any sort of judgment on those who make this choice when it is too damn much.
However, I would want very serious restrictions/checks around it. These so-called liberal European countries that do this do so in a really draconian way IMO. It's up to the doctor, basically, not even so much one's close relations and I've heard of a few horror stories where a lucid person protested the idea of being killed by the doctor only to be ignored because the doctor felt this person was brainwashed by religion or whatever and so went ahead and euthanized them against their will. It must have been either Belgium or the Netherlands where this happened. It was a nun that was euthanized. Something like that ought to be straight up illegal and grounds for murder charges. If someone still has the ability to refuse being killed then killing them is murder, plain and simple. You don't get to decide for people that they shouldn't go on living or that their life is not worth living when they don't want to be euthanized.
Also, placing such a decision in the hands of a stranger who feels nothing for the dying person is just gross. You find one of these cold hearted folks who only think in robotic, factory terms like how much medicine and food you're consuming etc. That cannot and should not be in the hands of a doctor. A doctor must be consulted (as part of the restrictions) but he cannot have the power to override another person's desire to continue living until natural death or at least until the point where they are completely incapacitated and cannot be brought back.
I also sometimes wonder if "easy" solutions like this esp where the elderly are concerned might negatively impact research and innovation around some illnesses that exclusively affect the aged.