I'm not altogether sure it's even about what children are taught, but about how they are taught.
My last 13 working years were spent in a bog standard secondary school working with children who came in Y7 with very poor or non existent reading skills. Naturally these children couldn't access the secondary curriculum subjects which required a reasonable standard of reading skills. There's a whole lot I could say about that, but my real point is that the prime reason that they couldn't read was because of the method they were taught by. A method introduced in the postwar period and hailed as being modern and progressive. (A method that is dying very hard, too and will be defended by many Gnet teachers .
There are big debates in the education world about teaching methods and they become politicised. I was horrified to find that a method that gives children the best chance of learning to read and thus access a whole world of pleasure and information was characterised as 'right wing'. As people well know, I'm very far from that!
But this happens right across the curriculum. There are teaching methods which turn children right off a subject, which, if taught differently, by a different teacher they would find interesting and enjoyable. The whole education debate hinges on not only what children should be taught but how it should be taught. It's far more complex than just saying they should be taught x, y, and z. And the debate will go on for ever, despite political intervention...