Don't get us wrong, the PlayStation Camera itself looks fine. It's no Kinect, but many gamers don't want a Kinect anyway. No, Sony's problem as we see it is in selling the camera separately instead of packaging it with the console.
Yes, it allowed Sony to keep the PS4's price down, which is definitely a good thing. But if Kinect actually winds up winning the hearts of gamers, then the PS4 might look less attractive; many Xbox One games will take advantage of Kinect in some way because developers know that every Xbox One owner also has Kinect. The same won't be true for PS4, and the PlayStation Camera might be underused. Besides, the PS4 pack-in title, The Playroom, uses the camera extensively. What's the point of including a PlayStation Camera game with the console when the camera is a separate purchase?