There are two responses to your inquiry:
1) If someone takes even a semi-literate approach to a new story that isn't based on personal prejudice and the story does not contain an obvious error or lack of effort then rational critics will rate it 2/8 or above based on their own personal standards.
2) If you take a personal dislike against an author or his subject matter you will entirely disregard the literary rationale side of any discussion concerning the story and rate it negatively based on your own personal, and probably questionably based, prejudices.
Hence why some WC stories get rated 8/8. Hence why some of the most popular stories on this site get 1/8 ratings when the general consensus is in that they deserve a 7/8 rating. The problem is not with the author but with the critic. Essentially you could answer your own question by taking the time to explore the ratings of stories in the Top Rated Category.
Personally I think having bad reviewers is worse than having bad authors because bad authors will get help sooner or later. If you have bad reviewers who can't tell for themselves the difference between a good or bad story then this site may have a new difficulty to deal with :) Generic judgements and not taking the time to actually read new stories but judging them on what faster people have judged them or based on the reviewers own prejudices is as detrimental as a crappy WC story. You can put the drawbacks of a site down to an individual target or a select group of individual targets but basically everyone is responsible for raising the general standard.
My boring moralistic outburst is over, I'm returning to writing Magellan 4 now :)