My main reason, is the schools here are terrible. They weren't before, but they certainly are now.
I don't want my children being taught to just get by, based on state minimums, that's so limiting. Which is exactly what most public and even private schools do. They teach to the letter of the law, and rarely beyond.
The few schools that offer gifted and talented(because let's face it, not all schools do, or can), even have limits as to what they can do. It's really not fair for the kids who NEED to be above "grade level", on some things, but maybe not all. Or even vice versa, the kids who need to be on a lower level on some things, but not all, fall through the cracks too.
It's a crappy system all around.
It works out "fine", "good" even for a lot of kids, because a lot of kids fall middle of the road, right on the path the schools follow. So they don't get lost, they don't fall through the cracks, and they aren't hindered at all.
But children aren't cookies made with the same cutter. They're all different, they're all unique, and if you can't cater the learning to them, how on earth will you ever know if they're even aiming for their highest potential, rather than settling for what's put before them?
Most people who don't know there is a world out there beyond what they're familiar with, will never go out looking for it. I feel, quite often, that's one of the downsides of most schools. Not necessarily their fault. I'm not saying they're all terrible, good for nothing, etc... But they don't have the resources, because this country doesn't provide them. We're a stingy bunch, that's for sure. Those who could benefit most from our tax dollars, our financial assistance, rarely ever actually get it.
But that's a much longer rant than I should probably put here.
Suffice it to say, I want to HELP my children learn, not force them. I want to provide them with ALL of the tools they will need to not only realize their potential, but shoot beyond it, too. I want to be able to see where they might have a weakness, or strength, and assist them with it. Rather than toss them in with a bunch of other kids and hope for the best. I want to give them a basic, solid foundation for later in life, teach them how to use their skills to improve(or gain) others, and allow them the room to grow and learn at their own pace. This way, when the time comes for them to leave my nest, I'm not just shoving them out and saying "love you, hope you remembered to learn how to fly", then giving them a great big push.
My children are as unique as any other, they don't fit in the mold people seem to assume children should fit into. I kinda like that. Parents are forever telling their children that they're special, unique, one of a kind. But they rarely ever actually treat their children that way. I'm somewhat bothered by that. I did it too, which is part of the reason why it bothers me. My kids used to attend public school, as did I, and things really have not changed much. This is how I KNOW schools these days, are failing our children. Even the ones that do okay. They're being robbed every single day of their own potential, and we(not to mention they) don't even realize it. We're as brainwashed as they are. .....
Because it's "right", and "normal"...
But, my kids aren't normal, and neither am I, so here we stand. They're doing far better now, than ever. On many subjects we are anywhere from 3-5 grade levels ahead of where they would be, in any other situation. Not because I forced, pushed, or poked them into some mold, but because that's where their minds lead us. The areas they struggle, aren't a big deal, because we know, eventually, we'll get it. We just have to work harder, or find a different way. In the end, it all works out.
It's not easy, it can be hard, and yeah for some folks is is isolating. There are many ways to remedy all of that though. You just have to find what works for you.
People always think things are odd, when they don't understand them. It just shows how ignorant they are(in the true definition of the word) and how very little their education brought them

They wouldn't find it odd at all if someone gave them all the tools and opportunities they needed to really reach their potential.
People sometimes put down things out of jealousy too. I say that with the utmost respect, of course. Some parents want to homeschool, but don't know how, don't want to give cause for others to think them weird, don't want to...(fill in the blank). But really in most cases, it's the ignorance preventing them, and nothing more.
I could find a million and one reasons NOT to homeschool my kids. But as time goes on, I've found those reasons are pretty petty. I can find a million more to prove exactly why homeschooling them is best-for THEM. Because that ought to be a main goal, not what's best for the parent, but the child(ren).