I've had this idea in the beginning, but we didn't want people to think we're only upvoting people so it'd put more buy pressure on zing.
I guess another step that could improve this could be if we on our side took care of the fee associated with sending the hive/hbd onto layer 2 so people could get 100% of the zing from their rewards - thus it costing us a little bit but not the authors who'd generally would have to swap for hive engine swap.hive and eat a fee doing so.
That said, we do have some social achievements cooking as well which we will allocate a small portion of the zing rewards pool towards, let's see if it still feels like a necessary addition back then!