Because the society just wants to prolong our suffering, and people are cruel. Nobody should ever be forced to live against their wishes. Why force someone to suffer until old age just for the sake of it, it is wrong. If someone wants to die, then their choice should be respected and others should have no say in it. It sounds so horrifying failing a ctb attempt. We should all just be able to exit peacefully without having to ever worry about the chance of the method failing.