I'm in a related business, and came from the newspaper side of the publishing business (Knight Ridder); I've never met on journalist that purposely was looking to just find something negative. I'd say that 95% of the writers just want to do their research well ... believe it or not.
Most of the feedback are corrections that could be solved by better research. Often writers don't fully understand their subject on short deadlines; its easy to misspeak in an article.
I do often read articles posted on SFGate.com .... but usually after they have been pointed out to me. Let us know what is said.