The main issue is that readers – paying or not – aren’t engaging with overtly magazine-like apps. There’s a simple reason for this: printed magazines work better in every way. They are a simple one-off purchase that can be used (both in a navigating and reading sense) anywhere. They are lightweight, easily shared and disposable. You’ve heard the arguments plenty of times but this first year of apps have done nothing to weaken them. Why would you buy an app when it only repeats the printed magazine?
Jeremy Leslie's thoughts are generally spot on, he is one of my favorite bloggers, and I am generally as inclined as anyone to embrace the idea of an iPadocopalypse when it comes to the current state of table application design. But I think it's a stretch to say "printed magazines work better in every way." Print doesn't work better for breaking news, interactive visualizations, collaborative real-time problem solving, blogging whimsical ideas that aren't print-worthy (a la The New Yorker), community, e-commerce, location-aware behavior or searching archives.
Right now many iPad apps are designed to replace what the print magazines do well, not augment what they do well with what the iPad (natively) does well. And that is the basic problem with most tablet apps today, especially the Adobe-produced behemoths that seem to be unfortunately gaining traction.
I'm oversimplifying Leslie's argument, he goes on to outline some new apps that he expects to be better, but I think that most people overcomplicate the problems publishers and marketers are facing right now. This is, of course, an opportunity to start over and do everything better.