Perhaps it's cynical rather than disingenuous. ~30% of people derive more satisfaction from seeing someone worse off than they do from mutual benefit - not even a zero-sum mindset, but a negative-sum one because such people are willing to incur a loss as long as it correlates with someone else experiencing a greater loss.

Put this depressing fact together with a highly networked communications infrastructure, and you can see there's a big economic incentive to talk shit about others. The US has an entire media sector built around the opinion columnists and radio/TV hosts whose whole brand is aggressive belittlement of others, or bullying as entertainment.