"It's mind-blowing. There have been reports that Mike Ashley wanted his own man and he inherited Sam and it's not for me to tell anyone how to run their club.
"But Sam's job was being lived out in the media. All these things the fans were singing like 'You don't know what you're doing' which then were taken up on talk shows and by pundits. It's madness.
"Let's have it right. Sam's been there for 24 games and they were 11th when he left.
"What is it about Newcastle? People there have to have a reality check."
Owner Ashley, who stands with the United supporters at Newcastle games, and his chairman Chris Mort are believed to have canvassed dressing-room opinion on Allardyce's style of play.
But Jewell believes that this demonstration of both fan-and player-power is bad for the game.
"Sam gave himself, and probably needed, about two years to turn it round," he said. "He only got 24 games.
"They'd had a lot of injuries but the reality is that, after two years, if he hadn't turned it round Sam wouldn't have had to be sacked - he'd have gone of his own accord.
"He didn't get a fair crack of the whip. It just doesn't seem right to me, although I wasn't surprised. That's the way it is now.
"We've had eight managers sacked from the Premier League this season already. That's almost half the top flight. Sam was a proven manager, but then again so was Kenny Dalglish, Ruud Gullit and the rest."