Depression doesn't allow you to do those things, Turtle. Mine is mild in comparison to others I have been around and I know I haven't seen the worst of it, but a true depression is like an anchor around your neck. Wanting to cast it off and not return to it does not allow one to do so. When you can't see the light at the end of the tunnel, train or not, that's a deep, dark hole to be in.
I'm glad for you that you have the demeanor that you don't have to worry about that. Some people don't have the wiring to bootstrap themselves out. I can do it, but I imagine it's a longer climb for me than you.
At the end of the day, he is responsible for the actions he took. But his father is going to have to live with the thoughts for the rest of his life that he failed his son, and in a small way, he's right. But not everyone can be saved. You can not help those who do not wish to be helped.
And the presented media and world around us do not show us the true horror of someone ending his life. The comparison that comes to my mind is Full Metal Jacket
vs. Budd Dwyer
(wiki link). I don't recommend watching the video of that one to anyone.