A couple of years (IIRC) ago I read that a major US corporation stated that new hires coming out of our school systems were NOT un-educated. They were un-educable!!
Hopeless, and public school spends approximately $300,000 per student for 12 years of school.
I have attended both religious schools and public schools as have my children. I have yet to find a bad one. A teacher or two, yes, but overall, they were quite able to teach those who wanted to learn.
I can't understand parents complaining that their child isn't a good reader. You are the parent. You'd better take up the slack because you brought that kid into this world, you are with them for 18 years, you are the one who is there at night, you are the one who has only a few kids around, not a huge group of them, you are the one who should be making sure that child keeps up.
The one common denominator among well-educated people is a love for reading. Since I was about 12, I devoured books as fast as I could read them. Not just dime-store novels (though admittedly a lot of that) but non-fiction books on history, science, technology and social studies as well.
I remember in high school working my way through Winston Churchill's books which allowed me to run circles around my history teacher at the time. I can still remember correcting him on a point concerning WW2 and it pertained to Germany declaring war on the United States after Pearl Harbor. My teacher maintained that it was the U.S. that declared war on Germany first. Actually, as I was able to point out, the U.S. declared war on Germany only after they had declared war on the U.S. first. Of course, I got the "why don't you come up here and teach the class yourself if you're so smart" attitude.
Point is, all schools can really do is give you a rudimentary understanding of all the various subjects. For any in-depth understanding of any particular subject, you must do your own reading.