On an individual level I still don't think this was the wrong decision and it's on Rashford if he doesn't put the work in to change the manager's mind. He needed this ultimatum really or nothing would change.
On a team level though it doesn't make sense to pick on one player when nearly everyone is performing so poorly. Others might apply themselves a bit better in training but it's about the end result on the pitch.
Also we keep being told the players don't have time to train, so I'm a bit lost on what the decision to single out one person and leave them out in the cold, but not do anything with anyone else is based on.
We have players who repeatedly perform appallingly and seem to either give up or lose their head, and Amorim keeps picking them.