It depends what the magnitude of the transgression is, and whether you are a journalist or non-journalist.
If you are a journalist, the faking of a quote, even if it's something as benign as, "Sally Smith, an 8-year-old from Chicago, said, 'I really love the clowns. They mak eme smile'" is punishable by the (journalistic) death penalty. No one was harmed, especially if 'Sally Smith' was herself made up, yet such a writer would have a very, very hard time finding work at a reputable non-fiction publication.
To a non-journalist (who, in this case, is anti-fossil-fuel), though, someone who worked in the Exxon PR department as an entry level job out of college and then worked his/her way into a respectable columnist position, would always have the taint of Big Oil Money...even if said columnist never fabricated a quote in his/her career.