Steemit has never had a good system, I don't expect new downvoting to be any better either. There is a ton of stuff on steem that should be flagged, the system has left it up to the judgement of those holding SP who are going to have varying ideas on what is shit and should be downvoted. What is the alternative? Maybe it should be consensus flagging by a large part of the community that doesn't really on vote power. Steem could be radically be changed, it probably never will though