1) Mum and dad don't have to be teachers. 1-on-1 instruction is so much superior to classroom education that there is really no comparison.
I think home schooled students can really benefit from a parent's creative curriculum that they probably would never get in a public school. One example I can think of is that when I was around 2nd or 3rd grade my mom bought one of those huge fact books and made it part of my daily curriculum to read something in the book and at the end of the day report to her some fact I learned. Before long I went through the whole book and was digging into encyclopedias for interesting facts, usually obscure historical information and after awhile I developed a reputation among my (public schooled) friends in the neighborhood as being a human encyclopedia. I really feel home schooling's flexibility cultivated in me a thirst for knowledge that may have went undeveloped in the crowded and rowdy public school system.
Also speaking of home schooling's flexibility when I was growing up my dad would get his paycheck every other week early in the morning so my mom would take us with her down to the factory to pick up his check. Since we were out and about on a early Friday morning my mom would look for opportunities for an educational adventure. One experience I remember in particular is at a park near where my dad worked there was a police officer on duty; she talked to the officer and explained we were home schooled so he showed my brother and I the inside of his police car and explained how everything inside worked and what it was like being a police officer. Having my mom as a teacher was like living inside a Discovery channel show.
Something else that no doubt helped was that my state in particular offered a great deal of support to home schoolers. In my first year my mom even talked on the phone with somebody at the governor's mansion for help on getting started. I feel the state really wanted to see home schooling succeed.