>I noticed something: most of the irritation came from a handful of people…

See also: Pareto Principle

https://en.wikipedia.org/wiki/Pareto_principle

Most people don’t cause problems, but the minority that do cause the majority of problems.

It depends what you consider a problem. Deliberate trolling is probably uncommon, but annoying people regurgitating what they've been told by mainstream media was, and is, all too common.