I was heavily downvoted for snarky and spiteful comments and ultimately hellbanned as I tryed to pack up my cynicism in elaborate arguments. The downvote privileged are pretty vigorous about protecting their privilege.
I don't think it's a trait of just large communities. Cynicism, negativity runs deep on just about any forum, comment sections and social media site connected to the Internet. The anonymity that the Web provides seems to reflect a widespread layer of angst (at least in western society) that's otherwise hidden/masked in the real world.