The great problem with government schools:
First off, with so many new regulations on curriculum, standards of excellence, funding, and so many other things, 'public' is a misnomer for these schools. These schools are not owned and operated by the public, and, in fact, have little control over many things at the local level. And now, thanks the well-intentioned but extremely crappy No Child Left Behind Act, every teacher in the country has to teach for the same test or risk losing much-needed federal funds. You also have no choice as to which 'public' school you go to. The school is only 'public' if you live in a certain district and are of the age that attends that school. Everyone else must state a clear purpose and sign in as a visitor. No, these are not public schools any more than a prison is a public building. These are government schools. The government controls them, and with the dwindling educational value, it probably won't be long before the proper term is 'government indoctrination centers' a name only barely avoided at this juncture.
The number one problem with government schools is that they are run by the government. Things that are run by private citizens must to well to get paid. If somebody doesn't want to pay you, all they have to do is do without your goods/services. If somebody doesn't want to pay the government, they go to jail. As such, anything run by the government can almost universally be counted on the be inefficient and crappy at whatever they do, as they have no incentive to do better. The primary exceptions are the military and some areas of law enforcement (a guilty concience can be almost as motivating as the pocketbook). This is why most schools are more interested in saving face than teaching students. As long as they can avoid a scandal, nobody gets fired and the money keeps rolling in while maybe 50% of the students they produce are capable of reading this post. Add to this the fact that the tax money cannot even be allocated to a different school even if one of them is so bad that over 75% of the students in the district homeschool or splurge for a private school, and we can easily see that why few government schools excel at anything...they don't have to.
The number two problem with government schools is that they are controlled by the government. Let's assume for a second that you get competing, private firms to actually run the school. You still have a major problem. The government still controls the curriculum and the standards for excellence. This makes the government school an indoctrination center. If you look throughout history, the government has grown almost exponentially since every child was given the right to a tax funded education (nothing is free). Think about it. If you go to a Catholic controlled school, you will likely grow up liking the Catholic church. If you attend a military school, you will likely grow to like the military. So what happens if you go to a government school? Why do you think the latest universal solution to all problems is another government program that only looks good on paper? In a government school, you will, of course, learn of the might of the founding fathers, but that will be downplayed compared to the secular sainthood granted to Lincoln and Roosevelt, the two men responsible for more government growth than all presidents prior to FDR combined. Everyone should be taught that government is a necessary evil that is to be feared. You will NEVER learn this in a government school.
Then there's the standard of excellence. Huge, bureaucratic, government agencies are not willing to go through the trouble of actually looking at anyone's methods to see if they're doing a good job. They instead come up with a one test fits all method of examining only the final product. This barely works if the raw materials are all consistent, but this system heavily favors teachers who are given good students. Teachers in backwoods areas where education is still, at the least unfashionable, and at the most, heresy are given horrible grades not because they're bad teachers, but because their students don't try. There are people who can't grasp certain bits of math and science. Not everybody has the potential to get a college degree. However, the government only sees the cookie-cutter, college bound student who is perfectly capable of learning trigonometry with the right teacher.
The third problem with government schools is that government schools are beholden to politicians. Politicians aren't interested in doing a proper job. They're only interested in getting re-elected. To this end, they will propose a short term 'fix' to the education problem, the impact of which will only last until election day. These often involve artificial measures of improvements like smaller class size (which often simply mean the teacher prints off 15 copies of busy work instead of 30), better equipment (the students waste time in class by surfing for porn on new, high-res screens instead of the old ones that only went to 800x600), or simply more funding (which means that now the school spends $30,000 per illiterate student who can only count with his fingers as opposed to $20,000). The only way a politician will ever fix the school system is by hiring somebody competant to do it for him, which amounts to a slightly higher form of throwing money at the problem.
Government schools fail solely on the fact that they are government schools and need to be eliminated. Can you imagine applying this logic to any other necessity? Imagine how crappy your grocery store would be if you were required to either shop there or pay for groceries you don't actually buy there and pay again to shop somewhere better. At the very least, imagine how much a school would perk up if students could actually take their tax dollars with them when they left for something competant.
On a side note, what are these homofascists (calling someone a fascist is 'in' right now) going to do next? The new Barbie and Ken companion dolls Susan the lumberjack and Frank the hair stylist?