Its only meant to reward users who already do that. Not incentives you to post more.

Members of this site have varying degrees of activity. Those who are naturally more active deserve more stakes. Everyone gets something according to their natural activity level. Just a way of adding a little bit more.

There are quit a few members of this community that make 20 posts per day...which comes out to 100-140 a week. They should be rewarded differently then somebody who only posts 3 times a week.