Context matters; how many of these images in the training data are taken from shock websites, and therefore associated with misanthropic commentary, versus legitimate sources like medical journals or historical pictures? Based on the samples posted by the author, it seems likely to be mostly the former. Whereas most discussions of burning a house down (not saying all, of course!) are probably in a neutral or negative context (e.g., news articles describing a crime).

"Understanding more about what exists in the real world" is a remarkable euphemism, btw.