The only main character I killed happens to be immortal, so he came right back... 
It's not about being brave. It's about what the story needs.
I haven't written a story that needs the character to die just yet.
OH, WAIT. No! I have!
I just remembered. I killed the POV character in one short story.
But, to prove my earlier point, the death was the point of the story - my MC got to see why her grandson kept pointing at the corner of the room when there was nothing there.