We homeschool for several reasons, and academics is way down on the list. We actually live in an area that is nationally recognized for its schools, but we know we're doing the right thing for our family.
When our oldest was about 4 I really started researching homeschooling vs conventional schooling. I read a lot (I'd NEVER make a major decision like this without researching it thoroughly), spoke to hundreds of ppl, and prayed with my husband many many times.
One of the books I read, "Inside American Education" by Thomas Sowell really opened my eyes. I completely recommend this book to anyone with questions about public education.
As to reasons, as I said, there are many. We like being in control of what our kids learn, and what they don't. We appreciate being able to have more control over their peer group--peer influence is CRUCIAL for character development, and I'd never just leave this to chance. But primarily, we wanted to be able to heavily address spiritual growth because it's my DH and my belief that spiritual and character development is more important than even academics (I'd rather my kids be ppl of integrity over geniuses ANY day). Fortunately, kids are naturally little sponges, so if all you do is put learning opportunities in their path, they WILL learn. Both of our kids read very early, and are learning at or above the levels of their conventionally schooled peers. That's typical of homeschooled kids. Finally, I just like spending time with my kids

. Yes, I'm partial, but I think they're awesome little ppl, and we enjoy being together. I can't imagine dropping them off somewhere and spending 8-10 hours away from them every day.
I should say that my DH and I were schooled in very different settings. I'm a product of conventional schools, and hold a Bachelors and a Masters Degree. My DH went to private schools and also has a college degree. I never saw us as homeschoolers, but after having done it for 6 yrs, I wouldn't change it for anything.