And this is what I've heard from people my whole life, but I never understood what they were getting at. What is it about a larger community that makes it impossible to organize in an egalitarian fashion? What is the common feature of large scale societies that allows them to organize?
Eventually I figured out that the common feature is centralization, and the obstacle that centralization overcomes is limitations in communication. Now those limitations are gone, and the need for centralization with it.
It's one thing to be able to communicate with people, it's another to be able to care about them. It's quite easy to logically arrive at the conclusion that all people should be treated equally and you should look out for the interests of all people equally, but to actually do so is quite hard. There's a leading theory in anthrpology of Dunbar's number, which is that it is impossible to properly care about more people than a certain number (usually given as being around 150).
I don't really understand the significance of Dunbar's Number. I've been aware of it even before that Cracked article where it was termed The Monkeysphere, which is how most people seem to know about it. It's an interesting concept.
But it doesn't seem too much of a stretch to me to objectively appreciate the notion that the people outside of your monkeysphere are just the same as the people inside of it. Society is a massive web of billions of overlapping monkeyspheres, and while yours may feel more important than others, that doesn't mean it objectively is.
I know that many people don't put so much thought into developing a broader perspective, and thus aren't likely to appreciate that. That's why there's a thing called Enlightened Self-Interest, which is very similar to what Gantolandon described. It doesn't exactly require much enlightenment, either. It's ridiculously simple to understand that other people provide products and services to you the same way you provide products and services to them, and if we don't maintain the functionality of those relationships with people we don't even know, then it's impossible to achieve anything beyond an agrarian subsistence lifestyle.
Property-based systems actually decrease enlightened self-interest, because they're so heavily based in competition for individual gain. They force us into a narcissistic tunnel-vision, that becomes a necessity in order to compete. The only we to achieve a comfortable life is to fight for a standing near the top of the pile of humans, so we must become callous. Short-sighted people think that being forced to contribute to public services takes away from their ability to directly invest in their own corpse-pile climb. This is why our culture is currently severely devaluing things like education and other public services. It's only a matter of time before people realize that many of our society's problems are directly caused by devaluing those services, and will begin to value them again. It's one of those cycles that we're constantly going through, similar to the longer-term cycle of extreme wealth consolidation -> crushing poverty -> radicalization -> violent revolution -> back to wealth consolidating.
Now to respond to GreatJustice.
As for capitalist owners being necessary in order to take "risks" and for establishing means of production in the first place... that depends on how late into the capitalist game you are. At our late stage, most of this is achieved through inheritance, and capitalist owners are so powerful that they can rig the game to benefit them even when their investments fail. If you don't see this happening right now, you're delusional. In early stages, inequality is negligible enough that you can't really argue that inequality played a significant part in that establishment.
Plus, you keep talking about wages. Any system involving wages in any form comparable to what we know today would not be social libertarian. Your wage is a roughly equal access to the total wealth of your whole community, not just in the single operation that you participate in. Hoarding of goods beyond what could be called your personal possession is also literally impossible, as such ownership is seen as fundamentally illegitimate.