A big part of a child's success in school has to do with parental involvement. Home schooled children, almost by definition, have highly involved parents. It would be interesting to compare home schooled children with regular children whose parents are actively involved in their education to see how that matched up.
Traditional schools are built on an industrial batch model where the goal is to get a certain percentage of the class to basic competency. So students are grouped in classes, taught for a semester, graded, and then moved on.
The Khan and homeschool model, in contrast is the mastery model. Students are individually taught at their own pace. They are not graded and pushed on. Instead they keep learning a topic until they know it. In traditional classroom education, the learning is variable while the time to learn is constant. Khan makes the learning constant and varies the time. Some students will learn faster than others, but all students learn to a high standard.
Khan is not just delivering a better classroom. He is offering a wholly different model of education.
To over-generalize: one-on-one teaching results in results that are about 2 standard deviations better than normal. Home schooling results are about 1 standard deviation better than normal.
This does not sound like an argument against home schooling. If it sounds unfair, that's kind of the point.
My issue with home schooling is the lack of variety and specialization. With only one teacher, the child just isn't going to be exposed to as many viewpoints as they would in a traditional school setting.
Homeschooling and un-schooling are actually quite varied. Un-schooling, specifically, is usually very specialized. Take Erik Demaine, for instance. He is the youngest professor in MIT's history - he was un-schooled until he entered college at 12. He specialized in mathematics because he loved it.
Homeschooling is still regulated by the state. Students must still pass certain tests, and often homeschoolers have a community of parents and children who get together to learn with each other at educational events geared specifically to their education. Both models have evolved, though they still have some cons. So, too, do public and private schools. Personally, I'd like to see us picking the best parts of various educational systems and putting them together.
