I really cannot remember a time, at least from the time I got married and had any conscious thought of having a family of my own, that I was not planning to homeschool. It was more like an intuitive decision, a natural action. So to delineate my reasons for doing so is actually quite an exercise.
Still, once we hit that first challenging year of formal homeschooling, I found I needed to be able to remind myself "why" I was doing this thing. And this year, when we moved to a small town, with few if any other homeschoolers around, where community life centers around the schools, where we were not only the new kids in town but the oddballs as well, I found I needed to really spell out, for myself, why I homeschool.
It all seems like one reason in my own mind:
Family unity. Raising our young Christians in keeping with their baptisms. An integrated life. A meaty education. Learning to think. Learning right and wrong, rather than how to follow the crowd. Real history instead of "social studies". "Sex education". The precedence of the family over the state. Really belonging to an organic whole instead of being lost in the herd. Making sure my children go out into the world as adults, not as large children. Imparting practical skills, not just head knowledge. Sharing a way of life. Restoring what is broken in the modern world.