An artist can make whatever he wants just like I can choose not to buy anything he makes. If you are in the Entertainment selling business putting politics in your games just pisses people off and lowers sales. When people say we do not want politics in games it means we don't want Propaganda games. Nazis being bad won't make anyone mad since everyone agrees they are bad. If we make a video game on a position of the refugee crisis then that is a problem since not everyone agrees what should be done.
Most people watch movies or play games to escape the real world. The last thing people want it to be reminded of it all the time. If I wanted politics I would watch the news. If someone made a game to just change my opinion on something I would just avoid the game. I want to be entertained not lectured on how to think.