First of all, how is using a "wireless communication device" (presumably any device that can send and receive data via cellular or Wi-Fi) a problem, but not two pilots getting into a serious conversation, say about union issues, the merits of Boeing versus Airbus, sports, where to go for dinner during a layover, whether switching layover hotels was a good idea, etc.
I've seen drivers of cars in very animated conversations with passengers, and cars and clearly under full control (drifting in a lane, changing speeds, etc.).
Second, as mentioned earlier, what about electronic devices incapable of wireless communication, such as e-readers, DSs, digital cameras and video recorders, and so on? This may prevent someone from filling out a bid sheet on a laptop, to be sent electronically later, but it doesn't prevent the shutterbug from snapping photos with a Canon or Nikon DSLR (or better yet, an older camera that uses 35mm film).