WikiSummaries is not related to WikiAnswers, so we cannot speak for them as to reasons why or why not. I can take a guess at saying, simply because no one has written one yet. Like WikiAnswers, it is a volunteer site. You could always read the book and write one for them to help out the next guy. The link to do so is listed below.
it hasnt
hasnt
He hasnt.
he hasnt
it hasnt
he hasnt
it hasnt
she hasnt yet ;)
No he hasnt.
it hasnt
no she hasnt
no he hasnt he plays for argentina