After a goalless first half, Newcastle drew first blood six minutes after the break thanks to debutant Callum Wilson, before another debutant Jeff Hendrick made sure the points were secured during the dying embers of the game.
The Hammers have now lost four successive opening-day Premier League games without scoring.
In an interview with Sky Sports after the game, Moyes condemned his team’s lethargic display against the Magpies, and admits the Londoners must improve.
"Didn't enjoy the performance, didn't enjoy the game. Those are my thoughts,” the former Everton manager said.
"We did not show enough quality and I don’t think it was officiated well but that is not the reason we lost.
“How far from last season? "Miles."
“Newcastle made it difficult for us but I would like to have seen more from us.
"Some of the decisions we feel aggrieved by but we will say that after every game, that is just the way I felt.
"We have to look at the next game and concentrate on trying to play better than tonight. We can play much better than we showed tonight.
"If we can get something in, it will help. As I said, the group who played tonight performed well only six weeks ago and we hoped to get another performance out of them but it was not meant to be."
West Ham will look to atone for their sins when they face Charlton in the League Cup second round on Tuesday, before traveling to Arsenal in the Premier League on Saturday.
