There are couple of reasons for that.

1. Since the post is targeted for new users most of the up-votes are also from newbies. Since the votes of newbies are generally not worth much the rewards are also generally lower.
2. Many of the upvotes have been given post the rewards deadline.

Though it is sort of a bummer I don't mind because I think in the long term this will pay off. This also highlights the issue of undervalued posts that the community has found useful. I am working on scripts to identify these kind of posts so that we can retweet them and it can reach out to more users.