I totally agree with you about most public schools pushing stupid curriculums and wasting money on stuff. If I had my way, critical thinking would be required all four years of high school, but we know the government and the corporations would never allow that because it's bad for their power and profits for people to see through BS easily. Generally though I think the problem with school is that it takes learning, which is something that children naturally are interested in, and makes it boring and teaches kids how to do the bare minimum for a grade. By the time they get to high school they're not interested in learning anymore. For example, I always excelled at reading and writing. I was in AP English for 6 years, but in AP, we didn't do any creative writing. All we wrote the whole time were formal literary analysis, which I hated. So I got bored and didn't do as well as I could have in those classes, I just did the minimum to get by.
My school is pretty good actually because it's a private school that kids have to audition to get into and have to perform well to stay. But it's gotten a little lax lately because the budget is in bad shape and they need all the students they can get in order to keep the program running. I have great kids in general, but there is one class that has most of of the slackers in it, and of course having all the slackers in one place is a recipe for disaster.