I don't think you get it. It isn't about reality. It isn't about one particular thing. These guys simply HAVE to be negative.
Some probably are just that way about everything. They are just glass-half-empty people. It's sad, but it just is. We all know real humans like that.
Others have just created their own little internet world in which they can spew their bile. It's fun for them. It provides an venue for them to swing their virtual man parts around.
The reality is that none of us really has that much of an idea what the future holds. But, VolNation can't stay afloat with one "let's wait and see" post with 234,000 likes. It needs controversy. Reason holds no fun here. If you want to be "liked," you have to pick a side.
And, frankly, negativity is easier. The script for Oscar the Grouch was not hard to write. Grouchy Smurf wasn't hard to predict. Just pick something (or someone) and hate it.
Plus, the Half-full people aren't "I told you so" sorts for the most part. So, you can get away with more as a Negavol. You just say whatever you want, and then when things actually turn out ok, you throw out an "I'm glad I was wrong." How can you refute that? It's the Kobayashi Maru.
But, if things do go bad, then you have the mighty "I said all along . . . ", and you can beat people over the head with it. You have strong medicine!!! You are a freakin' psychic! You have great internet status and all your internet subjects must bow before you!!!
It's all in good fun. Don't get too bent out of shape about it.