To be honest i really don't think the DRM nonsense really did that much harm. Sure as an informed gamer you will know about it, but most potential customers probably don't or hardly know what DRM is. And besides the plans were reversed so it really doesn't matter.
Price is important however, and can easily make someone who is in doubt and does not care for Kinect choose PS4.
Their are two more important things though. First is worth of mouth. Many people have an informed gamer in their friend group or family. And so when looking for a new console they will ask that person. And since that person knows that the PS4 is probably more bang for the buck if you don't care for Kinect or any certain games, he/she will recommend a PS4.
Then comes the most important argument however: The Playstation brand has always remained stronger than Xbox to begin with. Sony simply messed up last gen with a price that was to high, and releasing later.
So really it isn't what Microsoft did wrong, it's what Sony didn't do wrong.
