I could be wrong in this, but in some countries having an education is a privilege - not a right or required by law. If we extended that thought to the public education system here in the US, then the teachers could then focus on the students who truly wanted to learn. Face it - not everybody wants to be educated, and the world needs janitors and ditch diggers and other unskilled labor too. I was taught growing up that I had a choice - I could work with my back or work with my brain. Since my dad was a general contractor, I got to "experience" the work with my back and decided I needed to get the education. (I have an M.S. in software engineering) The problem I see there is that the teacher's unions would drop a brick as then we wouldn't need all the deadweight they bring to the table, and those teachers that actually can teach would be employed while those that can't can join the students that didn't want to be taught in the first place.
As for my kids, I had them in private school. However, private schools now have the same problems as public schools with the voucher system that's in place. Now we homeschool because A) We know the teacher personally, B) Our "student" gets one on one help when he has problems grasping a subject, C) He can progress at his own pace instead of having to learn at the rate of the slowest person in the class and D) If we need to use corporal punishment, we could. When we take him into public or he attends a homeshool league function, he is a respectful gentleman unlike the unruly brats in the traditional school system (And we find the "unsocialized" homeschooler jokes/arguments hilarious. Those that don't homeschool have no clue how much quality "socialization" goes on - but I'll leave that for another discussion)