It's merely condemning all christians to go to this extreme for their children (and possibly others) to believe in god as much as they do. I don't see anywhere where it said that spanking your kid for not reading the bible or believing in a god is a common practice among christian faithful

There's no point to pointing at the bible incident. He was beaten to death for not doing his homework. The other incident was a day before and, unless that was the first time he was beaten, is unnecessary information to the actual story.