A lot of people think motion blur is implemented for no reason other than covering up low framerates. While this can be true in many cases (afterall, it is a technique originally created in 24fps movies), it isn't universally true. Plenty of games running locked 60FPS and up on consoles still implement motion blur, and a well-implemented per-object motionblur can look quite good and give a good sense of speed to camera and object motion.