Well, that's not too different from what Man United has been doing for the last years. I'll admit it, Man United has played amazing football from time to time, but in the long term, many games have been about establishing control and getting a lead with 1 or 2 goals. After that it's pretty much just getting the time to tick away, not by defending insanely or anything, but not really bothered too much about attacking either. So on that front I don't think Moyes is too different from Ferguson, and it's not like Man United are playing football like Barcelona, as in still putting 95% into attacking even when they are ahead.
As for Moyes not winning any trophies, I don't think that is something you can hold against him. He hasn't had the resources and he has been stuck with a paper thin squad for a long time. When he came to Everton, they were almost equal to a club like Wigan for example. No big resources, a fairly thin squad and he took that and turned it into a club that would go on and finish in the top8 almost every year for a decade. He even took Everton to Champions League where they were defeated just barely by Villareal who would later go on to have a very successful year. So I don't think anyone can hold that over his head. As for not winning any trophies, that part is not just about skill but also very based on luck. Everton made it to an FA-Cup Final and had to meet the champions, Chelsea. While another club like Portsmouth who won it, had their game against Coventry. So there is a lot of luck in winning a cup trophy as well.
In the end, Moyes has the attributes that are the most important ones that Ferguson had. Integrity and being a very solid manager. He stuck with Everton for over a decade despite the fact that he could have left them earlier. He's used to making great transfers without too much money, and while Man United is one of the richest teams, they aren't Man City or Chelsea for example. He seems excellent at motivating his players and getting 100% out of them. His accomplishments with Everton are amazing, and in the end he is a much better suited manager for Man United than someone like José Mourinho for example.
With all this said, Man United might still have a tough season next year. But I feel like that would have been the case even if Ferguson had stayed for another year. City will make some new transfers due to not winning anything this year, Chelsea will get José Mourinho (most likely) and he will want to buy some players as well, specifically a striker who can score. Arsenal will finally have to spend money in order to keep up, and you have clubs like Liverpool and Tottenham, both will continue to improve under their managers. So the competition is bigger and tougher than ever, and even if we don't win Premier League next season, that won't necessarily be Moyes´ fault.
IN MOYES WE TRUST.