The reason for this disaster was all explained in 1955 in the landmark book by Rudolf Flesch called Why Johnny Can't Read. The explanation was that California had eliminated the teaching of phonics, which is a method of teaching kids the sounds and syllables of the English language, so he can put syllables together and read big words. California replaced this with the so-called Whole Language method of teaching reading.
Whole language is a method of teaching kids to memorize a few frequently-used one-syllable words and then figure out the meaning of the book, probably referring to the pictures on the page. Whole language looks upon reading as a process of having the kid create the meaning of the stories, whereas phonics is a process of reading and understanding what the author wrote. Millions of dollars were spent to accomplish this changeover in method, and it ended up a total disaster.
The Whole Language method is a fraud. With Whole Language, kids never learn how to read words of more than one syllable, and that's why, when they get to the 4th grade, American children fall behind on all the international tests. You would think that California educators would wise up after turning out 25 years of functional illiterates, but they haven't. They are as determined as ever not to teach phonics, which is the key to all successful reading.
Listen to the radio commentary here: