No doubt it is theoretically possible. Would airlines invest in the money required? Especially when they are not prepared to invest in decent communications over Africa and still use HF.
A few scenarios that have happened to me, I wonder how the remote guys would deal with it?
1) A light aircraft without transponder blundered into our path. We saw him visually and took violent evasive action. As far as I can see a remotely controlled airliner would have hit him.
2) Circumnavigating CBs. I very much doubt the controller sitting in a comfortable chair can have the same degree of self preservation and interest and understanding of the associated turbulence that the pilots at the front get. A good Captain and First Officer assess the weather using the radar and visual clues, discuss the options and then agree on the best routing to take.
3) Autopilot dropped out in cruise at FL350 and would not reengage. Aircraft flown manually to destination.
4) Medical emergency, doctor on board, immediate diversion required.
5) Outer pane of flight deck window cracked in cruise. Aircraft did not detect it. There are so many things in an aircraft that can be spotted visually but are not detected by the automatics and sensors.
Pilots can still do things that no automated airliner can do, ie look out of the window, see a runway and visually approach and land on it. I don't think there will be pilotless commercial aircraft flying around in the lifetime of anyone reading this forum. Maybe freighters.