True, but since ATC's DO provide info to FCS's
As an Air Traffic Controller with both the Army and at one of the largest airports in the midwest, I'm sorry to say, but this post couldn't be any more distant from the truth. We provide absolutely no information to the FCS on aircraft and at no point does our hardware communicate anything to the aircraft. We receive information from aircraft and that is it.
All navigation on the aircraft is done by completely internal equipment that the pilot can override at any point.
Air Traffic Controllers (the people) issue instructions, which the pilots are obligated to obey, but in the case that they believe an instruction from ATC is unsafe, they have the final say (and will ultimately be liable for the choice, but that's another matter).
Runway collisions become ever more likely the longer a compromise situation exists.
Runway collisions? Ground control is done via visual observation from the tower by a human being. Also, the pilots have windows which they can see out of. Yes, there are radar systems on the ground to back up some areas that are harder to see on large airfields, but visual control is still the primary method of control on the ground.