Ars Technica has posted an absorbing article about the short history of Internet and cell-phone access for passengers
aboard commercial airplanes, which does a lot to sate my curiosity about the factors holding it back, and gives some ideas about what to look forward to. An excerpt: "Despite the volume of equipped aircraft, we're still in the early days and the continued availability of mile-high WiFi is certainly not guaranteed. It's an expensive, long-term investment to supply consistent and usable broadband Internet service at 35,000 feet. Surveys show people want access, but it's unclear how much (or even if) they'll pay for it. Aircell says that 20 percent of passengers on equipped cross-country flights use its service, but it's mum about numbers on shorter segments."