I'm very rarely on a plane. However I take the subway every day, and I'm extremely thankful that Tweetbot, Reeder and Newsstand cache everything so that I have something to read. I also don't consider the subway a niche or isolated pocket.

I just don't buy the lame justification about not always being connected. If you don't want to be connected, turn off your damn phone. Don't insist that everyone else shouldn't be able to enjoy their time the way they want to because you associate your mobile device with stress.