Interesting piece. You wrote:

To me, the really detrimental isolation aspect occurs in the public schools themselves. Kids need to interact with lots of different age groups to grow up with a balanced outlook, sense of real security, competence, and sense of time and place, and their own roles within their respective communities.

Do you think schools that have grades K-8 do better than schools that are K-5 when it comes to interaction? When my son was an 8th graders, he would read to the 1st and 2nd grades for community service hours. I think the goals of this activity is to achieve the type of interaction you detailed above.