... the Cpt keep the hand on the throttle but also the FO can call STOP instead of just calling the malfunctions! Imagine a time sensitive scenario with a 150 (or greater V1), the last think you want to do is try to process other information except REJECT! Correct me if I'm wrong!
And what happened when you have a Cpt in training on the left seat and an IP on the right seat? Who is doing what and who is really responsible of what happen?