Public Schools use to teach the core academics needed to succeed in the working world. Now schools have become involved in social experiments and have taken on the roll of "parent" in much of this country's public school system. There is way too much time given to dealing with social and behavioral problems as compared to direct teaching of academic skills. Having worked in Public Schools for the past 12+ years, this is my observation.
More money is being spent, not on teaching academics, but on dealing with repairing the torn social fabric which used to be taken care of in the home and within the general community.
If the schools don't teach solid reading skills by 3rd grade, and the fail to teach solid arithmetic skills by the end of 4th grade, kids will continue to achieve below their potential.
As you noted, it's just so obvious only people willfully blind can fail to see what's going on.