One reason is that it has a LI-ION battery which I would not like to have in the cargo-hole, the other is that in the very unlikely event that a comms failure occurs, there is at least something to work with for the flight crew.
A case of
une crise énorme de grandeur Americain, n'est-ce pas?
You don't want to know how often I've heard:
capt to atc: we need to delay our departure
capt to passengers: ATC forces us to delay our departure.
No, not really. But thanks anyway.