Hmm, I'm guessing that it is because yours and EY's stance (if I understand it right) is along the lines of "every life is sacred, every life is great" and is a common sentiment on LW; and that's why your comment was upvoted and mine downvoted (probably misunderstood as "he has no valid argument to offer and so disguised this fact by tapping out"). Again, this is only a guess.
I certainly don't think consciously, or act as if, "every life is sacred, every life is great".
Nevertheless the people I care about personally, and myself, are still far more likely to die from some disease that is curable but is not eradicated due to lack of funds - including most or all causes of natural death - than due to the actions of madmen, gunmen, evil biology professors, or their tiny intersection.
Which is why when I read news like in this post, I think: "why am I wasting my time thinking about this?"
A Ph.D student in neuroscience shot at least 50 people at a showing of the new Batman movie. He also appears to have released some kind of gas from a canister. Because of his educational background this person almost certainly knows a lot about molecular biology. How long will it be (if ever) before a typical bio-science Ph.D will have the capacity to kill, say,a million people?
Edit: I'm not claiming that this event should cause a fully informed person to update on anything. Rather I was hoping that readers of this blog with strong life-science backgrounds could provide information that would help me and other interested readers assess the probability of future risks. Since this blog often deals with catastrophic risks and the social harms of irrationality and given that the events I described will likely dominate the U.S. news media for a few days I thought my question worth asking. Given the post's Karma rating (currently -4), however, I will update my beliefs about what constitutes an appropriate discussion post.