A new essay by Glenn Fleishman discusses the reasons for the winding down of his iPad-only digital publication, The Magazine, including an in-depth look at Apple’s continued treatment of Newsstand as a failed experiment. Launched around two years ago as a digital-only periodical, The Magazine focused on reaching iPad users via Apple’s then-fledgling Newsstand app and online store. At its height, The Magazine had nearly 35,000 monthly subscribers…