It's just funny that Americans have to contend with 2000 channels, and 60 different specific news sources, and the confusion that it creates, and the junk that we get to see is hilarious.
Hollywood has to appeal to the broadest audience, and when it comes to most social and economic issues, America is progressive. Because of that, the messages that are in Hollywood movies tend to be, for instance, pro-environment.
You could feel America starting to ease up a little bit on racism, against blacks in certain pockets, and then suddenly The Cosby Show bubbled up and it was the right time for it.