I happen to disagree with your view on AP classes. My AP Languange and Literature classes greatly prepared me for what to expect for college-level work. Granted, it also depends on other factors like the school system, the program within the school, the teacher, and most importantly, the student.
A lot of people seem to think that just because you take an AP course in HS and pass it that it equates to automatic college credits. I don't know how it works in other states, but in VA, in order to receive credit in college for AP, you either had to earn a 4 or a 5 on the AP exams.
I know a lot of people who are in their senior year of college, who don't know how to write at all. The one thing I've noticed in many people's papers is a lack of voice, or personal sense of style.
I could go on and on about this, but I'm done with my rebuttal.