The reason your formulation ("How has X not been subjected to Y yet?") comes across as potentially objectionable is that it implies that his being brutally murdered would be an understandable, and almost logical, outcome of his editorial decisions. (Compare: "That guy skips so many classes. How has he not been expelled yet?")
I know that that's not what you meant at all, and I don't mean to be critical. I'm in agreement with the sentiment of your post. But this is why so many people are uneasy about that particular remark.