Without records recognized by the school system, it could have been a real hardship for them.
You are offering an opinion in ignorance. You might want to see to that.
I'm presuming you live in a state with homeschool regulations. Not all of us do, and our children do just fine. There's no need to transition into high school. My eldest did home school through high school, and now he's in college on almost a full scholarship. Many others go to community college for high school and earn dual credit.
If you look further into this story, you'll find that CPS and the public schools let these children down. The school system had these children in school until two years ago, and CPS investigated twice, and no one did anything for them. Now they're suddenly interested... but only in passing the blame.