My kids came home from elementary and junior high schools with papers "corrected" by the "teacher". Gag! I had to make up for the poor quality of teachers at home. My middle son ended up teaching his AP courses as the "teacher" didn't pack the gear to do it. My son and the people he tutored in the evenings achieved a "5" score on all the AP exams. He finished with a 4.33 GPA behind his girlfriend with a 4.86 GPA and valedictorian of her graduating class.
As a footnote, after serving in Iraq and Afghanistan with the USMC, my son returned home to earn a BA in Business Administration and a 2nd BA in Physics. He's a real estate broker as his primary self-employment and has a Class A CDL that he uses to drive flatbeds to earn additional income. He's fluent in English (native) and Spanish. One of those white males that is the target of the modern dumbing down movement. He doesn't have any kids at age 36, so I'm not really ever expecting to have the "grandparent" experience.