United have struggled in Moyes' first campaign as manager and sit seventh in the English Premier League after 22 rounds with 11 wins, four draws and seven defeats.
The reigning Premier League champions have also been eliminated from both the FA and League Cups, although they remain alive in the UEFA Champions League.
United's poor results and form have led to speculation the perennial league contenders will sack Moyes less than a year into his six-year contract but Ferguson has rubbished the suggestion, saying consistency and patience are critical to long-term success.
"I can never understand why clubs change managers so quickly," the 72-year-old said.
"They (board members) must discuss the qualities of the manager they are going to offer the job to (and) you must look at his CV – the character, the philosophy he has, surely.
"Now if that is the way they have gone about giving the man the job, why don't they persist with it? It seems so stupid to me.
"There is no need to go down that road (of sacking managers).
"United can do anything. They have got that great philosophy and history, they will always do well."
"This year for the first time it really looks as if five or six could be involved (in the title race), so it's a great Premier League," Ferguson said.
"It's still not an easy league to win. I think the English game is the most honest and is the hardest league to win in terms of the competition you face. You can lose to anyone."
