These are not special reddit features, you can make generalizations about any group of people that isn't randomly chosen.

That doesn't mean that "the group of people in your office building" or "the group of people in your neighborhood / town / state / country" or "the group of people that you bowl with" or "the group of people in your extended family" are "hiveminds" though. That is like accusing this piece of granite (http://upload.wikimedia.org/wikipedia/commons/0/0d/Granite_Y...) of being gray.

In my experience, "hivemind" is just bullshit people talk about when they want a way of saying that they are better than other people, but can't bring themselves to commit such a crime against modesty forthright. You'll notice that it is never "reddit is a hivemind, and oh yeah, I totally agree with it." It is always "reddit is a hivemind, and I disagree with it"