Kids are meant to play all the time, not to be taught

I'm watching a talk,
Conference on Alternatives to Compulsory Education - Peter Grey - April 27, 2013
Youtube link: http://www.youtube.com/watch?v=J7gZw0KJXVQ

Around the 15th minute he presents research by people studying hunter-gatherer groups from around the world. These would be analogous to adivasis in India.
Very interesting observations about the way these disparate groups treat their kids:

• Kids are not directed / told what to do / what not to do / scolded
• If they play with dangerous items like machetes, it's assumed they know what they're doing, and if they get hurt, they'll learn. Parents don't bother.
• There is no concept that kids need to be taught.
• Kids go off to play all the time, as soon as they're fit to leave the parents' side, and by the time they become adults their play naturally morphs into taking responsibilities for the community
• They have never seen kids whining about anything in these groups
• Kids grow up to be self-organizing and self-directed.

About the groups themselves,

• There is no chief of the tribe, no hierarchy. Decisions are made by consensus.
• There is no concept of telling a person what to do. It flows naturally. It is assumed everybody will individually arrive at the right thing to do when given the freedom to make choices. They don't need to explicitly make laws : there are natural laws and they act naturally.
• These are complex, rich cultures with their own music, dance, and they have huge store of knowledge of different species of plants and animals around them. There is an enormous amount that a person in these communities have to learn. And they learn it entirely on their own, without adult supervision.

Before this, observations on mammals:

• All mammals are found to play when young. Unlike other species, mammals have a lot to learn while growing up. Through their play, they learn the skills needed as an adult. So kittens play with their prey : they may catch a mouse, then let it escape, then catch it again... We see puppies and cubs brawl with each other : they're practising hunting.
• This play is essential to the mammals' growth and thriving.
• Humans have the most to learn : not just skills relevant to the human species, but in each social group, the skills and behaviours relevant to that group. So naturally, they need to play the most.

I know there are various rebuttals to this, most of them having to do with treating these cultures as backward and treating ourselves as advanced and better than them. So explain how those cultures managed to preserve the planet beautifully for thousands of years (since the last Ice Age ended), and we managed to absolutely mess it up in just a few generations.

No, you say? There are huge islands of plastic floating in the middle of the Pacific, farthest from any human settlement. There is black soot depositing over Antarctica and accelerating melting of ice caps. Undersea corals across the globe are in a mass die-off due to increasing acidity in oceans. The only spots still preserved are the inaccessible ones or those where we're not allowing civilized people to go. YES, we ARE messing the planet up royally.

Instead of shuffling between past and present and making a stupid brainless contest out of adivasi Vs modern, think how we can combine what we're learning from all quarters, so we can think about how we want the future to be.