The Scotsman believes that United have lost all their tradition and class through the sacking of managers.
The Red Devils have employed several bosses since Sir Alex Ferguson retired in 2013.
Moyes, Louis van Gaal, Jose Mourinho, Ole Gunnar Solskjaer, and Erik ten Hag held the permanent job over the years.
“Manchester United had unbelievable traditions. They brought in their own young players, and they didn’t sack managers,” Moyes stated, speaking on the Stick to Football podcast.
“When Sir Alex Ferguson wasn’t doing so well, they didn’t do it. They stood for something which was admirable, that this club means a bit more – that bit of class, which dropped away at that time (when I was there).”
“He (Rúben Amorim) is in a completely different situation now,” Moyes continued on United’s incoming head coach.
“I was really forcing it, to take over the champions at the time, so I was coming from a different (perspective). At the moment, the players might now be saying that they need to step up because the manager might be coming from a stronger position.
“Manchester United have really talented players. Getting into Manchester United in the situation they’re in, they can only improve – because of that we might see an improvement in their performance.