RE 1. It has already been mentioned that food analogy is not a good one, since we are not talking of not providing education to smarter kids. And, this is not a binary issue, there is a whole spectrum of intelligence.

RE 2. The previous post does not say "every kind of diversity is automatically good". But I certainly agree that social and intellectual diversity has benefits for all parties.

RE 3. "Smart people do well and often have smart children", well it is not genetic though. While often "smart" parents have "smart" kids because they value education and know what to push. It is an oversimplification to say that education is equal to "smart". And sending a smart kid in the worst school would not affect his smartness. Especially now with Internet, if he is that smart and gets bored, then he can learn what he wants on Internet. Being a free country does not mean necessarily you can act freely against the collective good. I believe that the whole intellectual spectrum of kids can learn from each other and together. I believe that smarter kids should be able to learn more if they want to, but I strongly believe in the benefits of having all kids together in the same school, from kindergarten to university. Some kids might need more time, some could learn more and/or go faster, but they will still benefit from each other.