%50-%50 rewards might not encourage not only newbies but many other users to produce new/quality contents. There's a high possibilty that a user may ask "Why %50 of my effort would go to someone else?"

HF21 will likely encourage users to comment more and more, however I have noticed that comments are not upvoted as before, under this post e.g.

Steemit even before HF21 was played between the users that have high rep and SP, now it has been much more. I don't think that a newbie will want to go on Steemit.

As said, let's see for a long term, but there is some reality that can't be played down.