Here is something that bothers me when I'm working in the library:
A little kid, maybe seven or eight, goes into the Juvenile section and starts to look at books. Her mom comes after her and says, "Not these books, they are too hard for you. You're in __ grade and so you must read books out of the ____ section."
What is it about this scenario that bothers me? Well, the little girl was only looking at Juvenile cooking books. She was reading them, and she was old enough to cook the recipes from them, so how were they too hard for her?
I think parents sometimes rely too much on groupings and grades that schools use to organize. I was homeschooled, and growing up I loved the library. I picked out my own books, huge stacks of them, and it didn't matter what grade level they were at. I just picked what interested me.
I think it's possible that this system of reading levels is taking the love of reading from children. To be repeatedly told that something is too hard for you when it really isn't has to have some kind of effect. Staying inside your age group of books means you will never be challenged by anything you read.
I have been reading from the adult and children's sections for a long time. My love of classic literature started when I was a kid, something that would have never developed if I had been limited in my reading choices.
Now, I'm not saying you should give kids just anything to read. It still has to be appropriate, and I think it is the parent's right to approve books their children are reading. However, I think the child should choose what he or she really wants to read.
And please, never tell a child that a book is too hard. You might regret it when he believes you and thinks reading in general is too hard to be bothered with.