Yes, it is a brilliant idea. This way, you don't even have to be on the plane to hijack it. Just take over the ATC center which is probably a lot easier - or duplicate the comms somehow. Gee, now a terrorist won't even have to be onboard the plane to crash it...
Smart.
Now if the plane instead goes to a CAT III alternate (lots of those all over as we all know) automatically when a panic button is hit, the idea is just outrageously ridiculous, not criminally stupid.
/ft