Just MHO. I'm an American and I was home schooled from preschool through high school (I'm now a senior in college).
My parents did home school primarily because of religions reasons. However, another major reason was because some of the schools around here are dismal in quality. For instance, I know people here who passed through high school with a 3.5 GPA (A- / B+ grades) essentially without being able to read. I've met adults who don't know that we had the American Revolution. If the schools in your area aren't good, and you're willing to put the time and work into homeschooling (it is a full-time job), I think most people can teach their kids at home at least as well as the local public school. That said - it can have mixed results. Depending on what state you're in, the regulations on homeschooling can vary drastically. Growing up, I knew a family that played the dice game Yahtzee daily for math class (multiple kids in that family are now grown up and still have massive difficulties reading and writing). I also knew families where the kids read college-level material before they turned 10, started calculus in Junior High, and tested out of everything they could test out of when they went to college.
I think the main advantages to home schooling have to do with customization. Every kid learns at a different pace and is motivated by different things. In a large classroom, pace, motivation, and material has to be largely standardized; in homeschooling, it is rather easily adapted. For instance, I have some siblings that excel in some topics, and my mom can adapt the curriculum to let them get ahead and keep in a level that's challenging; for other subjects that they have more difficulties with, she can spend the time and tutor them so that they get the grounding they need before moving on. In high school, I was able to create a couple of my own courses based on my interests. I was basically doing projects similar to Freshman college assignments where I researched books, primary sources, interviewed people, etc on subjects that I was genuinely curious about. This gave me a big advantage in college because I was already used to pursuing projects on my own with little outside direction and because I knew a lot of background knowledge in the area that I want to go on to research.
Socialization is definitely something that needs to be addressed. I think this is something that I missed out on a bit - when I was little, we lived about 30 minutes from the nearest town. I saw people outside my family once or twice a week at church activities. When I was a teen, my mom made a big push that we move somewhere closer to town, and now she's driving my siblings to different events and activities multiple times a day. They're a lot better socialized than I was.
I think it's definitely possible to get decent socialization with homeschooling, but just like the quality of the rest of the education, it takes work, it takes being proactive, and it doesn't happen with everyone who homeschools.
I do think homeschooling isn't for everyone. Like vodkafan said, that 6 and 1/2 hours can be a lifesaver.
I'm not sure if I will homeschool in the future when I have a kid / kids. I think I could put together at least a decent education, but I love my work, and I'm not sure I could stand being home with my child the great majority of every day. It will probably depend a lot on where my husband and I are at in our lives at that point, what kind of schools are in the area, how well my kid(s) do in those schools, etc. If there's a great school that my kid enjoys, that's definitely my first option; but if my kid was having trouble in school, homeschooling would be an option I would look in to.