Why are you judging the merits of an article by the author and not the content?
So instead we judge by the author - i.e. is the writer at least trustworthy.
Your advice is good to take in general: don't trust what you read without judging both the credentials of the writer and the content the writer is putting forth. But to dismiss it based only on the author is shortsighted. I see nothing in your reply specifically about the content of the article, does anything else truly matter? Sure, take the author's history and intentions into consideration, but at the end of the day the content is what matters.