I agree - up to a point. I don't agree that schools are all doing a miserable job. You know the phrase "garbage in, garbage out"? It really does apply to K-12 students.
I've taught 10th-12th grade for 4 years now at an inner-city style school (59% minority rate, 78% free/reduced lunch), over a variety of Math/CS subjects, including Precalculus, AP Calculus, Honors Physics, and AP Computer Science. You'd think I would have the top of the stack, the elite students, if you will. If I do, it demonstrates the problem with some U.S. Science & Math students in the 21st century: the students at some schools (at least mine) have no desire to put in the effort required to master a difficult subject.
Students are looking for classes they can pad their schedule with that look good on college transcripts, but which require very little work. If it's an AP class, they want the AP teacher that gives out extra credit like candy, assigns 3-5 problems a night for homework, and gives "open book" tests.
I came from a tougher school of thought, so in return I expect work from my students; I assign 1-2 hours worth of work every night, every test is "closed book", every quiz is unannounced, and there's no such thing as extra credit. You should hear the crying of unfairness and cruelty. (The funny thing is for the 4 years I've been at my school, my AP class has had the highest passing rate of all AP courses taught at our school.)
My AP Comp. Sci. course, for 3 years in a row, was filled with ambitious MySpace, Facebook, or other "texters" who thought a CS course was going to be something where we sat around all day and wrote the next "How L33T are you?" quiz. Some thought we'd be writing the next Line Rider game the 1st class. When I tried to get them to understand OOP, or to think of what a Model & View architecture really meant, it blew their minds. A simple assignment (almost pointless, but done anyway to try to get something out of them) of picking an everyday real life object and writing down all of the things it's made of and things it can do, netted me about 20 papers all describing a pencil as being made of lead, eraser, and plastic, which can write and erase. Deep stuff.
You should have seen how well they handled writing a simple "Guess a number" game. Basic IF structures (logic) completely eluded them.
It's not their math skills that was hurting them (although you'd be scared to see how many AP Calculus students I routinely teach who can't grasp working with reciprocals or fractions in general work) - it was their inability or lack of desire to employ critical thinking skills. If it wasn't something that could be put on the back of an index card (to cram the night before) or typed into their cell phones (to cheat from the day of the test), they wouldn't do it.
We have to get past that laziness, that lack of work/study ethic, in K-12 education before we tack on anything else. CS, done well, cannot be learned in any meaningful fashion if there's no desire to use reasoning, deductive logic, or problem solving skills.
I pray it's not this bad at other K-12 institutions around the country, but I'm fearful that it's the same everywhere. It's the chief reason I'm pressing onward with my MA or MS to get my foot into the door of college teaching. I know you still get your share of lazy students there as well, but they might just want to work hard and pay attention, and I won't feel like I'm just spinning my wheels every day I try to teach another young mind. And I'm fully aware that I'm not helping the problem, if I'm even able to, by "bailing" on the K-12 arena, but there comes a point when your work begins to feel like an ice-cream salesman standing in Fairbanks, Alaska.....you just have to move your stand to somewhere you can get something done.
P.S. This year the county canceled my AP Comp. Sci. class and rolled my BC Calculus course into my AP Calculus course as an "independent study". Due to budget cuts, having 12 or less students means the class gets folded. So much for even the wannabe texters...