Board Books. For Big Kids?

Last week I packed up most of the board books in my 
six year old's room. Since then, I've been constantly 
repacking them as my eleven year old unpacks them. 
Trying to understand how his brain sees them makes mine ache.
Board books offer great pluses for all young readers, and young
readers with autism may especially benefit from the direct presentation of books like the Max & Ruby board books of Rosemary Wells.
Max's First Word is a classic of cute pictures and gentle humor.
So are Max's Ride, Max's Bath and the others.
But doesn't a time come when these must be put away?
Isn't almost twelve too old to spend time on these?
What does he need from them that each must be read more
than one hundred times?
Is it that he wants to read but doesn't want to spend more than two minutes on any book that isn't Mother Goose or song lyrics?
Left to his own devices, he flips through a chapter book as quickly
as a picture book. And no, he isn't memorizing the words. 
The page numbers, sometimes, but never the words.
I'm still unsure how to handle this.
What do you think? Does your child do this?
What do you do?