I agree with @holden—desperation. It’s about ending the pain. In the end, the pain is depression. I don’t care why you are depressed—if you lost all honor because you lost billions of dollars and can no longer support your family, or you lost honor because you chose the wrong side to fight for, or if you just murdered your wife and don’t want to live without her or in prison for the rest of your life, if it’s chemicals in your brain, or whatever. You just can’t see anything but pain forever forward, and you can’t put up with it.
Should we have to put up with permanent pain? Is it cowardice to end it?
Well, I suppose it depends on whether you believe that it is reasonable for people to understand that the pain won’t last forever. Personally, I think that you are in a kind of altered state of consciousness when you take your own life, and reason is no longer a part of your mental make-up.
Bravery and cowardice are irrelevant. They assume a person takes their own life for reasonable reasons. They assume it is not brainwashing of some kind.
When you are in that kind of pain, it seems unfair. It makes you angry. If you’re angry for people letting you be in pain, for letting you be alone and unloved and uncared for, then a public suicide might seem like a good way to get back at people. If you think you’re doing everyone a favor, you’re more likely to do it in a private way.