Nemesis Destiny
Adventurer
I started playing when I was 7; I don't think age has much to do with it, but then I was always reading way above my level, according to the tests.Then you have to go into why that term was used as opposed to Marshall, etc....
Again, why 4th edition probably isnt the best to use to teach people with, and why there is an age range on it, and I do not think the younger players included in that fit, and such another reason parents should be involved.
Since we are talking about 7-11 year old in the article, what is the age range for the PHB?
I also didn't need any guidance from my parents on the matter. I think most kids figure out the difference between make believe and reality around the same time they figure out Santa Claus isn't really a fat man in a red suit with flying reindeer pulling a sleigh full of presents around the world in one night.
The ones that have trouble with that, maybe, need some parental guidance. I had a friend in one of my earlier groups like that; he took it way too seriously, and his parents didn't want him playing. He had other issues though, and his oddball gaming habits were a symptom and not the root of the matter.
Most of my other friends' parents at that time also had a problem with the game, but it had nothing to do with their kids; mostly ignorance. We played with them anyway, and they mostly turned out alright.

So, I see what you're saying, but making it a blanket statement that all kids that young should have parental guidance when playing RPGs I think is a bit extreme.
One of the major reasons I liked it at the time was that it was written at a level I found challenging, and therefore engaging. Those books, and the game itself, I educated myself in ways that elementary schooling could not. I was thoroughly bored of the things aimed at my age group, and found them to be excessively "dumbed down" and unappealing. I liked that I had to look up some of the words in the PHB and DMG in the dictionary, or when they could not be found there, figure out what they meant in context.
That said, I was, and still am, cognizant of the fact that I was atypical in that regard, and agree with there being a suggested age of 12+ on the books. Putting a big ESRB-style stamp on it that says, "T for Teen" or whatever, and saying "you must be this old to buy/play it" would be a little much. Book of Vile Darkness, sure, I agree with the sticker they put on that for the most part, but the core books? Nah.