Designers Have Certain Responsibilities
Some random thoughts on random topics, it seems:
Being a game designer generally gets you no respect outside of nerdy circles. It doesn't have the same cache as being a novelist or a movie producer.
The media doesn't pay much attention to the industry until a game is blamed for something, in which case the publisher and designer are held accountable.
Games may be regarded as propaganda, criticized for the lessons they "teach" by those who disagree with the topic of the lesson. No matter what you do, someone will object.
Games, like other forms of entertainment, are often the scapegoat: if someone commits a crime and they own a game, then playing the game "made" them commit the crime.
The degree to which a designer takes responsibility is largely their own choice. The author's take seems to be that you should form your own opinion about what is harmful, and refrain from doing it.