Some people use homeschooling as an excuse to not give a damn whether their kids learn anything or not, but these are the minority. I view the "unschooling" thing in that light, and I think that where there are successes in unschooling, these are kids who would have done well in whatever environment.
Many parents view homeschooling as an impossibility, making several invalid arguments, such as that they don't have the time or the educational background necessary to teach their children, or that their children need the socialization provided by public schools. But these are all things that can usually be easily worked around.
Time can be a consideration, but that's only a valid excuse if your real reason for wanting public schools is to have a taxpayer-supported babysitter. This may well be a valid concern, but let's not pretend that it's something other than what it is. What it comes down to is whether you want to invest time in your children's future. I didn't homeschool my son because I wasn't aware that this was an option at the time, but while he was enrolled in school in Long Beach, California, I did have to invest a fair amount of time in after-schooling him because he wasn't getting what he needed. I went so far as to purchase the teacher editions of the textbooks used in a couple of his classes. Despite being a single parent, knowing what I know now, I could have homeschooled him, and I wish I had.
As for educational background, as far as I am aware, no state currently requires parents to hold a teacher's certificate to homeschool their children, although some states are friendlier to homeschooling than others, which are more beholden to the teacher's unions. Today, in particular, there is no good reason why a parent couldn't homeschool their children. There are so many resources available, from homeschooling curriculum to all sorts of online homeschooling resources, even fully online educational programs that can be completed at home without anything required of parents. Of course, by passing the whole job onto a virtual school, you'll lose some of the advantages of homeschooling.
By networking with other homeschooling parents, a parent's expertise in one area can be called upon to teach that subject to other children, while other parents contribute their own expertise or help in other ways. In most, if not all, school districts, you can still avail yourself of the resources of your local public school in areas that you might have a deficit. You are, after all, paying taxes to that school whether or not you have a child enrolled. While homeschooling our nephew, we enrolled him in the music program at the public school, and later he joined the school's drama club. That's it; the rest was done through homeschooling.
One thing that amused me was that when we first notified the school that our nephew would not be returning the following semester, the school principal told us that we would need the permission of the school and that we would have to submit a teaching plan to the school. Not so, and we already knew that, but we let him go on about it for a while before we told him that we didn't actually have to do that. Regulations may vary in other jurisdictions, however.
One of the things he said we would have to do was to include a section on Maine history that would include the history of the Native American tribes that inhabited the area. We weren't actually required to do that, but I thought it was a good idea, so I bought a book on the history of Native American tribes in Maine and included that. One of the amusing things was that I learned that they didn't teach that in the local public school.
As for socialization, as
@Don Alaska says, there are plenty of options, many of which do a much better job of that than the public schools are likely to.
To avoid his having to make any uncomfortable explanations, we sent our nephew back to the public school for his senior year so that he could graduate with a regular high school degree, but that's not a necessary thing. We just thought that might make things easier for him.