You're not forced to use a cell phone in order to fly. The radiation from the phone is not concentrated and directed at your entire body. It's a different frequency and intensity. A lot more time has been spent studying the dangers of RF from consumer phones than the dangers of these new machines based on medical devices that require lead clothing or lead walls for safe use.

You're also exposed to a variety of radiation when you fly in the high atmosphere or eat a banana. It doesn't mean additional radiation from insufficiently tested machines is a good idea.