Most people who have hit 10x the original free steem power given tend to stay with the platform so it is an effort to retain it's user base. By having steem power converted to steem slowly it keeps large sums of money from leaving the pool quickly. It's the first of it's kind and you have nothing to lose unless you choose to invest money to make a bigger impact on posts. It's at least offering rewards that sites like Reddit and Facebook don't. They keep all the money generated by users content.