It's probably only morons who haven't contemplated suicide.
And some very bright, talented, and indeed, courageous people have, unfortunately, succumbed to the urge that comes from the deep pain and utter despair of true clinical depression.
Now, I will say this. Someone who has to kill their family and/or friends in order to get up the "courage" to kill themselves is pretty cowardly. But these are the people who keep it so bottled up, who can't even talk about it, lest someone call them a coward. Indeed, they probably ridicule others for expressing the weakness they hide.