I don't think you need to watch people die horribly to have a pretty good idea of what sorts of things will kill you.
Top three posts on that page right now:
What, exactly, do you think you would learn by watching any of these three videos? That a bullet can kill you? Were you really ignorant of that fact before? That police might kill you if they see you attempting to murder another person? I can almost see your point with the head-in-the-sand mentality on the third video, but not really. We all know that there is violence in the world, and if you want to be educated on Russian/Turkish/Syrian violence in particular, there are more appropriate subs than this for information.
No. This is not educational. This is morbid, sadistic curiosity at best. Taking any sort of pleasure in viewing this sort of material is indicative of poor mental health and/or a lack of morals. I will go so far as to say that anyone who chooses to subscribe to a subreddit full of this sort of material is a blight on humanity.
You can have whatever opinion you like on the moral standing of people for plenty of issues. Homosexuality, abortion, adultery, or any number of other issues are morally ambiguous to some people, and wide open to debate.
Taking pleasure in witnessing people die is not open to debate. It is wrong. Period. There is no justification for it; there is nothing ambiguous about it. If you enjoy these videos, you are morally deficient and sub-human.