You touched on what I was going to say...
I don't know the details. I don't know his son. I do have a small inkling of how hard he was pushed over the years through John's posts.
A kid who is a B student, who is told over and over again that his football future is going to vanish if his grades plummet, and STILL let's his grades tank so badly that schools won't touch him - is passive-aggressively telling you he doesn't want to play at that level. Getting average grades in HS is like asking someone to breathe. It's stupid easy unless you are actively trying not to get them.
He may love football and enjoy playing it with his friends, but letting his grades go by the way side (and knowing the consequences of that) is a sign that doesn't share the dreams of his father. It just is.
So, maybe instead of plotting how John-boy is going to get his GED to go to Jr. college, transfer and redshirt at Div III east-bumf*ck, send Easter hams to the coach at Div II Mt. Nowhere in hopes of another transfer, so that maybe he can leave college with $50k of debt, no worthwhile degree or skills, and no shot of even being camp fodder in any professional league you might want to take this opportunity to re-evaluate the path he is on.
That's just my opinion though....