Suicide and public suicide should be separated when we talk about this. Personally, I think that suicide is something that someone who genuinely feels they have no other choice should be able to do. I mean, I really hope that isn't the case but having read that letter by Bill Zeller, I think it's fair to say that he made his case pretty well. As an atheist, I have no moral issues with it or anything.
Public suicide, though. Anyone who does that is a selfish, fucked up narcissist, frankly. It's a fucking horrible thing to do. Ending your own life is one thing but to do so by smashing your body to a pulp against the concrete while children eat nearby...that's fucking horrendous. There's no other way to describe it. It's a violent, terrible act that serves no purpose other than to inflict pain on other people. It's unjustifiable on any level.
but like I say- An individual has the right to choose. Not to be morbid, but I can foresee a future when I'm old in which I will simply act to end my life. I'm not depressed (quite the opposite) or suicidal but there's a good chance that, one day, I'll be helpless and infirm. Possibly insane. I've seen it happen and the thought of it terrifies me. Before that happens, I will kill myself. Simple as.