Everytime someone starts talking about suicide (either pro or con), there seems to be an instantaneous division of people into two categories. One (called "Shiny Happy People" by some) says "Suicide is WRONG WRONG WRONG and you are bad/evil/wrong/stupid to even consider it!" The other (called "selfish attention hogs" by others) says "You're stupid and you'll never understand, I bet you've never been unhappy a day in your life!"
The first reaction, I have often found, is based in a deep-seated, culturally-enforced fear of death. The second reaction is often an over-reaction to the first. Neither is a particularly good reaction.
Personally, I feel suicide, like abortion, should be the individual's choice. I know it sucks for you if you're the person left behind, but it is not the job of anyone to suffer so that you don't have to go to a funeral. That said, I strongly wish, as I do for abortion, that people are not driven to suicide as an option. People go on and on about stopping abortion or outlawing suicide, and very rarely bother to address the underlying issues which make people consider doing these things.
I hate people who make suicidal gestures. I hate them because they give a bad name to people who can no longer live their lives (especially those who had no choice in the matter*) and need a way out. There are some people out there who just do not belong in this world - do you really want them to continue to suffer?
As for all this nonsense about "if you're unhappy, change it," there is nothing more likely to make someone feel even worse than that phrase. The depressed person already feels bad and self-critical, and telling them that only confirms their worst fears, that they are horribly deficient in some way because they can't be happy. I have been on both sides of this fence, and I can say with certainty, "If we could, we would."
See Also: thoughts on how religious proscriptions came to be, Shiny Happy People, alt.life.sucks, libertarianism, The Ones Who Walk Away From Omelas
* Say, people paralyzed in car accidents or victims of genetic diseases. Sure, there are people who remain cheerful and happy in such circumstances, but others are not and cannot.**
For example, my husband has standing orders with his friends that, if he can't wipe his own ass, they are to kill him, because he probably won't be able to do it himself.