I agree that life is valuable, and that one should seek help, but for someone who is depressed it just isn't that easy. I don't expect you to understand what is going through the persons head (no offense intended), its not exactly logical and its definately not rational.
the thing a lot of people just don't see is when these people have asked for help. fourcams thread was his cry for help, no he didn't ask for it directly, but he said enough that people became concerned, they helped. depressed people often cry out in their own way to their family, but their family has seen the transition from normal to depressed, and thus the crys were to subtle to be noticed. where as an outsider could have looked at the situation and said "somebody needs to do something cause that dude is going to kill himself."