That assumes perfect knowledge. As mentioned in the article, these moderators often do not understand what they are getting into until long after they have committed to the job. Once you have quit a previous job, moved, setup your new life, only then do you realize your new "brand consultant" job means watching kittens die all day.

Jobs like this also open persons to realities that we normal keep tucked away deep in our brains. We all know that cops don't investigate most reported crimes, but that doesn't come up very often for us. A facebook moderator sees the crimes, sees the lack of response by the police or anyone else, every minute. Repeatedly, every minute. Nobody can appreciate what this does to ones' mental state until you have been there.