Originally Posted by HomelessScientist
This makes sense -- but does not apply when parked with the engines shut down, which is probably the case during an extended wait for deicing.
But if you think about it it has nothing to do with the engines. It has to do with the process it would take for many people to get to their laptops (in the overhead bins) and how long it would take for everyone to power down and restow their laptops (again in the overhead bins often). I had asked a pilot about this one a couple months ago (as I too was curious why the phones were ok after landing and not the laptops) and it was exactly the time and movement issues. It is time consuming to get everyone to log off their puters and put them away.