Your thinking about it from the western point of view where we are conditioned to believe that it is the ultimate sin to kill yourself... Remember we were considered slaves or work labor, and imagine if slaves had the believe that dying is better than living with out freedom or with out our dignity... Shit we'd be ready to fight and die no matter what the consequences, so to nip that in the bud the first thing they planted in our heads was the fear of death, dying and wanting to take control of our destiny...
To us suicide, at that age may seem like an oxymoron, on because we are not equip to think beyond the perimeters that we are programmed to think in.. But from a person that age it may be due to the fact that they choose not to go out in diapers, with out their dignity, seeing their friends grow old and die honorably , witnessing their own children grow old and start to die..
Man the subject really touched me one day, one I saw my Grandmother, for the last time, and my young dumb ass, at the time, said what most would say to someone up in age, I said wow Grandma what a blessing to be your age isn't it... She looked me in the eye and said, whats so blessing about it, I am blind, in pain everyday, all my friends are dead, the food is crap, and all I want now is to die..
I looked into her glazed useless eyes but was still able to see the truth deep in her soul, and for that moment I was her... It was the first and only time I felt that connection with her, she was not always a easy person to connect with, in life..
Since then I started contemplating my own mortality, and this is one of the reasons why I try to live my life full, with no regrets, appreciating everything I have, and what freedom I have , so if it ever gets to the point where my life got that heavy, or to the point where the docs to me the curtains are ready to fold, at least what ever I do, would be based on what I feel, not some arm chair quarter back who thinks they know whats best for me...
In the end the right to choose is what freedom is really about, and if you can't even contemplate how you would prefer to go out, believing that there is a good way and a bad way, well chances are you have never thought like a free man...