"User" generated content on the internet is mostly bots, HN included.
Opinions that seem too radical or stupid to be believed are often bots, or NPC humans repeating bot content that they read somewhere else.
On the flip side, there's plenty of just very dumb people out there. I play enough games that involve VOIPing with others that I can confidently state such.
You forget to mention trolls. The best way to handle a NPC propaganda parrot is to deliver them an even more foul piece of propaganda and observe .. vs disagreeing with them, that they would enjoy.