I'm guessing this is just a general internet behavior where people imagine others that they don't like are having some extreme emotional response to something. Then when one or two people do actually respond that way they use that to reinforce the idea that all the other people must be feeling the same way, are lying, or just don't exist. In real life you're only exposed to a limited amount of people so you would probably have to go through a few regular people to find those with extreme reactions. Online they are easy to spot and everything else is just noise. I suspect most of it is done knowingly as a troll attempt.
I distinctly recall seeing this behavior on this site when DSP won his bankruptcy. Lots of drive by "LOL look at all the angry people" comments when most people were begrudgingly accepting it despite it not being the outcome they expected or desired. That or doing a "this is how Bernie can still win" but not being mad about it. Could also be the ones actually mad tend to not let it go and keep mad posting giving the impression it's more people than it is.