Yes, nice article indeed!
I don't know if it is a fandom thing though. I think people do this everywhere over social media; not just on the matter of shows; but on the matter of a lot of other stuff--politics, sports, games... It's probably to an extent the anonymity it offers to folks.
Or, may be it is just a phase--a long phase--when the world is adjusting to the immediacy of communication. It's illusory, but for fleeting moments, it makes you feel closer to a whole range of people and topics; but, it also gives you a curtain to hide behind. It might take time for folks to learn that it is not quite so cut and dry.
I think people will learn eventually that working with others is better than getting to be proven right.
PS: I know I have been a negative flag bearer here myself, but I don't think I have attacked anybody. And, I rarely tweet anything other than news stories i like (to my five followers). So. As in, I don't think I am being a hypocrite by saying this.