IIRC it's a size and power thing. You can emulate most of what a ring laser gyro does with good accelerometers and that's the better choice for most devices needing long battery life and compact size. Ring laser gyros (while small) are not that small last I checked. A quick google shows you can get them in about the size of a pocket watch. So potentially a good case addon for those that need it without the cost/power usage issues that would hit those that don't.