Economics drives everything in Aviation these days, the bean counter is King!
is there a NEED for pilotless airliners? Pilot error? why would a ground based "pilot" be any less likely to make an error than one or two in a cockpit on board?Could a ground based pilot have made the right decision to the A320 that ditched in the Hudson River, or would they have got the Sioux City United Airlines DC-10 to a survivable crash landing?
Liability, simply put pilots are a liability to an airline. Automation places the liability on the manufacturer. This is the selling point above reduction in salary. My response to your other questions is in the post above.
Grounded...