In theory, the audience should.
In Steemit the content is rated or is intended to be rated by the users of the platform. Those creating the content get voted on by those who like their published article, There are some efforts made by some communities to address this issue and reward those who provide quality content for the platform.
Who decides what content is good is ideally down to all of us. The vote we give at the percentage we give is meant to determine how well we like the post.
Unfortunately, things do not always work that way. People will vote to their friends posts. These are going to be the ones that are most visible to them. They are also with a good chance going to be mentioned in the same circles that both move in.
There is not enough time for everyone to read everyone else's post and give each a ranking, The voting power and the resource credits would also not allow this.
For a new member to the community trying to gain the SP to interact and can take some time to achieve. Gaining the visibility thy need for their writing to be seen by more can be an uphill struggle on a muddy hill.
There are some with a big vote that can make the difference in if a post gets a high reward. There are also communities that do this too, by the use of accumulated votes when they find good articles to promote. Quite a few communities have established Discord servers to help promote posts that are under valued.
I think some of those communities should undertake to leave comment for some members to improve their publishing. Not just passing by a post, These communities want to promote the good works on the platform, Yet they help very little to raise the standards in some cases.
The goal of gaining a higher reward is a good incentive to want to write better quality and presented well content. There is little done to accommodate this through education. To achieve this and improve the quantity of quality content I think a body of people would need to be paid a wage to do this full time. Maybe a team for each major tag.
The reader should be the judge of the content and represent this in the reward they share. The gatekeeper should ensure no abusive content is permitted.