iOS is a walled garden and it will be as strong an argument as ever, regardless of how long iOS has been a walled garden for. Also, don't you see how having to buy your privacy for 15£, even for 0.01£ is ridiculous? And to your last point - a parent can easily bypass all that bullshit if they wanted. They could let their kids use a normal computer without any walled gardens. What's to stop them from seeing 4chan or motherless or anything like that? Nothing. And nothing will unless you force all of society into your dystopic vision of a safe world for kids.