Well POS has its benefits as well such as mining authority dictates or depends on the amount of coins you possess regardless of how powerful your computer and hardware is. Well it would give the person more incentive to keep the coin than to sell as well due to the notion of the more you keep the more you can mine. It is a unique system on its own, but some people might not prefer it as oppose to PoW which stresses only on massive amounts of computing power.