From the comments to this post regarding a new law that mandates rote learning in place of critical thinking in Florida schools:

All education is intended to serve the purpose of the educator. The Puritans taught reading so people could read the Bible; the 19th century saw schools go to an hourly schedule for the purpose of training future workers to be slaves to the clock.

To that end, I conclude that public education today has not failed at all, but has produced exactly what its government creators wanted to create: a semi-literate, docile workforce, susceptible to manipulation and untrained in critical thinking.