Flagging is always subjective since the value is subjective. I am not going to say anything about @berniesanders since there are a few people that he flagged and deserved it. His methods may be unorthodox but he's doing a pretty good job sometimes. ;)
For flagging to work correctly, the community needs to work together and decide what's valuable and what not.
I think one of the things to consider when thinking about downvoting someone is how many views did the post have, how many comments did the post receive, then how many votes it received. Votes are the iffy part, there are people that do buy votes, (but it is hard to figure that out), and then there are those voters that just follow along on someone else's coat tails for curation rewards. So yes value is a subjective thing, but if a person looks at the whole post picture, then they may be able to make a subjectively valuable decision. I will use your/this post as an example: 88 Views, 19 Comments, 57 Votes. Value=$138.68. Is this post really worth $1.57 per view? Some may think not. Is it worth $0.57 a view probably more realistic. So where did the really valuable votes come from?A whale, a whale curation trail,or purchased votes. I don't know, if I spent two hours researching I might be able to find out. So yes it is all a subjective decision when deciding to downvote, I have heard people say the samething about upvoting, but that is not true and an entirely different topic. Just my $0.030 point of view.
If a post has a higher potential reward, it will appear on trending/hot thus more people will be able to see it. If they open it and comment that is their decision. From personal experience, I get more comments on posts that are shorter than on the longer ones since there's not so much content people have to read, so it's easier for them.
If a post is of quality and it gets hit by a curator but it still has only a few votes does your system still applies to it? It's an interesting idea but it's too automated, there are many more factors to be taken into consideration.
I think that the only solutions are an organized team/community who can deal with the flagging.