Comics books good for kids?

My son loves graphic novels.  Here are his two favorite series:

I was dubious at first. But, he read over 1,000 pages of the Bone series. Since then he's written three of his own graphic novels.

This article makes the argument that comic books can be good for kids. What do you think?

http://www.huffingtonpost.com/common-sense-media/comic-books-for-kids_b_2832507.html