The most apt analogy (to my experience) is that in general, suicidal people don't want to die, but it's like they're trapped on the 20th story of a burning building and sometimes the fire seems to be under control but right now they're nearly overwhelmed with smoke and the heat is bearing down, and they're at a point where jumping seems like the best alternative.

And how relieved they could be if a fireman could put out the fire, or pluck them from that ledge to safety.

In the same analogy, there is still a time when jumping really is understandable; there are situations (Robin Williams comes to mind) when suicide really is a rational option.