Personally I think the reason kids don't read today is the wealth of YA books written by people like the author of this piece. By the time you are "old enough" for those books you are also old enough to want some sort of challenge, not what is ultimately a children's book that also makes vague allusions to "adult themes." But I also don't think this matters, vast majority of people don't read and that is not new, trends will go up and down as things go in and out of popularity, reading will come back into popularity.
For the past decade or so literature has largely been going through the motions and not producing anything which is meaningful and representative of the times we live in, so interest fades. Plenty of good books but nothing to shake up the literary world and give everyone that kick in the ass they need.