I never read the book, but what I see isn't so much people afraid to go outside physically as they are afraid to look outside mentally. Regardless of all else, people can see (1) scary stuff a'happenin out there, and (2) all the noise and social/media BS.
Averting eyes is the easiest course of action. Why go through the effort of weeding out the BS, for the reward of some highly depressing insight into how fucked things are? It doesn't compute mentally, emotionally. Only to a masochist. Knowledge brings pain, at least the kind of knowledge we need.
Even for the weirdos who do still desire news, they are given plenty of off-ramps to take before getting to anything worthwhile. Traditional media's been hollowed out from a dozen different angles (really too much for me to go into now) and when people try going online or to "alternative media" they're likely to get something even worse. People who liked the distaster-porn aspect of the news seem to have been captured solidly by online conspiracy peddlers, who are in turn captured solidly by state and corporate propaganda pushers.