It's sillier still to apply those generalizations to a "9-year old" with a beard and who made other 9-year olds cry to their mothers saying he made them feel stupid.
I know plenty of examples of 9-year olds who are more mature than many 20 year-olds I know.
Plus, 9 years isn't all that young to be watching or talking about porn. Perhaps just one standard-deviation from the norm (just a guess, based on my personal experience).
I'm also not sure what exactly the alternative to "free rein" is with regards to porn (other than blocking it completely). I don't know about you, but I'd rather not have anyone watch me as I jerk off to porn, much less my parents. I'm sure they would want to be there either (at least I hope so).
BTW, did you know it was only a few centuries ago that 15 year olds were wed and started families?
The great thing about this story though is we know how it ends. The boy who jerked off to hardcore pornography at the age of 9 (or younger) is all grown up and he's not a murderer or a rapist. Instead, he's won recognition for his intellect, and seems to be an all-around OK guy.