Some of the anger is a bit pointless, like "right wing media person said thing".
Plenty of it is justified – about the government, society, personal living situations, low level gripes.
But anger is the overriding emotion. Any idea discussed is phrased as a rebuke to some opponent of said idea, real or imaginary.
@tomw I think Twitter leads people to waste time shouting into the void or preaching to the choir or arguing with trolls and propagandists. It's the illusion of making a difference when actually there are better ways. Meanwhile, being on Twitter has a negative impact on people due to the constant flow of rage and controversy.