I am a college instructor, and I have been for about 7 years now. I'll be upgrading to professor soon, so I can tell you first hand that your observations are quite correct. The undergraduate education system of the USA is considered to be the laughing stock of the academic world. However, our graduate schools are perceived as the best in the world. The reason for this is the utter failure of our public primary schools.
Think of it this way. The average high school graduate in the US can only read on a 6th grade reading level. They come to me, a scholar in the field of Computer Science, and I have to try to teach them complex mathematical ideas that are only truly expressible in a new language. I have a couple of options. I can either dumb down my course to give them a chance, or I can maintain my integrity and demand that they come up to speed. The answer is that I have to do a mixture of them. If I taught as I was supposed to, my student success rate would plummet and my perception scores would be low, hence I would be fired. However, if I make the course too easy, I've polluted my own field in the next generation. Instead, I try to ramp them up with basic skills, but push them just to the edge of what their minds can actually handle. I also try to encourage them in other areas of study outside my own. Most of my students consider me a very tough but fair instructor, and most are grateful for my help. However, I do fail a larger percentage of my students than other instructors. Most have gone the field pollution route.
This is a serious problem in our society. One thing we could do to fix it is stop pushing college so hard. Many of my kids would be better served in a tradeschool than a university, and yet they are pressured to come to me. They waist 4 years of their lives, learn nothing usable, and then end up back where they started.
Oh, and one last thought. About the perception of the rest of the world. If you have a Bachelor's degree, that basically brings you up to par with the high school graduates in other countries. That also brings you up to the level your grandparents in the US had when they finished High School. We need to stop the degradation of the primary schools, but we never will. No child left behind has basically ensured that all future generations of Americans will be too stupid to find their a**hole with both hands.