That only works if you assume mind control is easier than physical control and a reactionary robot. We have robots that react to external stimulus already. For example, DARPA's robotic mule can react accordingly when kicked in the side. A VF-1 is sufficiently advanced to be a large, standing machine with some kind of reactionary control system like when the VF-1D fired its backpack thruster to attempt to stay standing or when Shin VF-0D is tackled and it tries to defend itself. Like I said, these are things we can accomplished now without mind control. Also the prospect of mind control is completely unrelated anyway.
Because it was a poorly researched idea that people were taking as fact about a show they were interested in.