If people are good, as you say, I suppose that it would work, objectively. But in that situation, there would also develop rules. The idea is that everything is for free - the idea of sharing. If this is the mindset, you could quickly convert that to having to share, because if this is how it is, it is supposed to be, and stay this way. This means that a possible rule could be, that sharing is mandatory. This means, that not sharing, is against the rules. If someone would want to be an individual, and keep their possessions to themselves (which wouldn't happen if if was perfect, as you described it, but still), they would be considered an outcast, or someone with independent thoughts, a rule breaker, and they would have to be punished for breaking the law. Is this starting to sound like nationalism?
What I'm trying to say is that, even in such a world, there would exist rules. If there would be rules, it means that they can also be broken, and obviously rule breakers, will be punished. And again that would be a world with restrictions, so it wouldn't at all be perfect.
But objectively, it would be good. It's just not realistic.