And that there is the problem.
Someone is looking for help and all they get in return is ridicule, condemnation, mocking and other related asshattery.
Sure, some people may have reasons for suicide that seem silly, but giving them **** for it has a much larger chance of reaffirming their view that suicide is what they need to do rather than convincing them otherwise.
If you know someone who is thinking about suicide and it's obvious, it's them saying "help me" to whoever will listen and what do they get? "Suck it up."
EDIT: Also take into account that different people have different thresholds for physical and emotional pain. Also, consider that just because something works for one person doesn't mean that it can work for everyone. People find strength in different ways, and telling them to suck it up isn't going to help a lot of people... it could even make things WORSE for them and lead them to this very end.