The problem is not the few parents who are homeschooling because their kid isn't getting adequate education, it's the larger majority of people who are homeschooling, or rather "unschooling". Usually because they don't want their kids exposed to "strange kids" (kids who are non-white, or do things that are unusual), or exposed to "bad ideas".
If you don't know, that's when parents are basically not teaching them anything - they grow up to be 18 and have the social skills of a 5 year old, math below a Grade 5 level (they can barely add two single-digit numbers together), and are completely hopeless.
Yes, there are people growing up literally as dumb as rocks. Their parents teach them that ignorance is good. Just vote Republican and all will be well with the world, and stay away from anyone with a different skin color as they're evil. Just stick around and do the family business and you'll be alright.
It's an alarming trend, and sadly, they outnumber the few kids who actually get a decent or better education at home.