You should probably start realizing that there are more devices than ever before.
They are all different and iOS/retina is taking smaller and smaller shares of it. Designing for that is designing for last generation platform-specific web and has little future.
You should probably start realizing that displays have higher pixel densities than ever before.
More and more devices will be providing high resolution displays. Designing for low-resolution displays is designing for last generation devices and has little future.
Of course, designers should aim for a solution that is as device-agnostic as possible. The linked article provides designers with a number of alternative ways to support high resolution displays. Perhaps their use of Apple marketing speak ("Retina") is self-limiting, but to dismiss the article out-of-hand for using that term is no better.
They are all different and iOS/retina is taking smaller and smaller shares of it. Designing for that is designing for last generation platform-specific web and has little future.