If you are ever looking for ammunition to answer this question with then you could head over to the Puffin Books Australia site where they have wise answers to the question.
Here is the first paragraph
Why should I read?
Excellent question! Why should you? Why should anyone? You could be doing hundreds of other things instead – watching a movie, preparing dinner, going for a run, or spending time with your family. But when your kids ask you the same question, you’d better have an answer prepared. “Because I told you to” probably won’t cut it. “Because it’s good for you” isn’t going to work either. At least not if you don’t have some solid evidence to back it up.
The paragraph I like the most is the last one on the page:
“Because it’s social”
I personally would add lots of other paragraphs to the article such as because some of your favourite movies come from really great books or comics, think Scott Pilgrim and 300.