My best friend drank himself to death, because he didn't want to live with the physical injuries that he had sustained, after an accident.
He wasn't an alcoholic.
He still had independence and some mobility, he was nowhere near the criteria that some people would deem as a 'pity' case.
He had a family, grandchild and good friends.
He simply didn't want to carry on.
I totally agree that if we think people have the right to end their life because they don't want to live with physical issues, then the same applies to Mental Health.