Yes, suicide is a totally voluntary decision...and, for many, it's a decision that allows them to end whatever suffering they may be feeling.
I feel it's a decision that should be allowed. When our pets suffer from the pain of severe and incurable health issues or injuries, we allow them to pass on with dignity and offer them an end to their pain. Why is it that giving our fellow man the same option under the same circumstances so vilified? Why is it considered so wrong for an individual to make the decision themselves to end their pain? Why is it that animals deserve to be put out of their misery and humans apparently deserve to suffer right up until their final breaths? How is it possibly humane to extend the life of someone who is suffering?
I just never understood why human euthanasia is so frowned upon. We may not have full fur coats, scales, or feathers, but we are all animals on this planet, and I see no reason why one species should be denied the chance to die mercifully, especially when it's what the individual wants.