There is only so much negotiating and maneuvering that can be done while the aircraft is under siege in mid-air. Therefore, the best way to put a stop to hijacking is by having high levels of security implemented by qualified and trained personnel both on the ground and in the air.
As the head of security for an airline, I can't ask my passengers to risk their lives and jump on a terrorist. This is why we need air marshals on every flight.