If the pilot wants to crash the aircraft they will regardless of who is sitting beside them so introducing anyone else solves nothing. What it does do is introduce another human into the mix, one that hasn't been screened to the same extent as the pilot who has always had the option of crashing the plane. One who is more likely to be under financial stress and one who is more likely to be exposed to recreational drug use. Brilliant. This is the dumbest thing I have seen in aviation in my 22 years full time employment.