I'm going to disagree with this, although I - obviously - understand how grim it is, and the effect it can have on the viewer.
For me, to refuse to watch someone's pain, or fear, or death is to deny their humanity to some extent. I may not be able to bring them confort, but I can bare witness to their suffering, and the value of their life as a life. It is - to me - to turn aside. It's to say 'this is to horrible to watch', while that person doesn't watch it, but endures it.
I'm not going to deny the effect it has on other people who think differently, and it's just my personal view - but refusing to watch this stuff sits uncomfortably with me.