Spending too much time on the web and watching television contributes heavily. Know a-lot of people who still find time to read avidly though, myself included. Some people these days don't seem to have the patience to get through a whole book. The change in trend to list based articles, though fun to write are an indicator that many people prefer snappier/easier going media. Or else were put off by the books covered in high school english lessons.
Consequence of a drop in reading could be decline in the printing/book production world which would be very sad. It is the last thing we need for more jobs to be lost.