Well, this is how Steem / SCOT work. Based on a reward pool that is distributed, among others, to those who are upvoted for their engagement. So in a way the intent of the engagement is a little blurry, except in obvious cases. Even some good engagement may drop, if there is no reward involved.
On Steem, maybe this is not wanted anymore, going forward. Possibly the STEEM / SP rewards will be replaced in time by SMT rewards, so maybe HF21 is only the beginning that prepares the terrain for what's next.