Why is actually more interesting than the title implies.
“Negative information is just much more diverse than positive information,” Jackson said. For example, he added, “If you’re talking about ‘The Odyssey,’ this new Christopher Nolan film, the top comment in a thread might be ‘I liked it’ — but then what else is there to say? If you want to stand out and say something new, you have to talk about something you disliked about the film.”
Jackson and his colleagues analyzed more than 2 billion comments from 2,150 Reddit communities and found that both threads and communities became more negative over time, and that semantic differentiation drove that trend — that is, negative comments were more semantically unique from what had already been said.