If society changes, the media will change to reflect it. In a related vein, violence in the media was recently the topic of a Surgeon General's report. However, contrary to the popular belief of practically every newspaper story since the Columbine incident, the Surgeon General reports that violence in the media really has no link to the cause of adolescent violence, and only a minor link to early-onset violence, far behind other things such as bad parenting and natural aggressive tendencies. Finally, there is vindication for those of us who have been saying all along that the media has been overplaying violence in the media. Of course, it should be that way.
Fighting is merely an outspring of conflict that manifests itself in a physical form.
The only thing that makes entertainment interesting is conflict, whether it be drama, or action, or comedy, entertainment is driven by conflict, simply because things aren't uniform, things are different, and conflict is natural. In a lot of anime, fighting occurs because there is genuine conflict there, there isn't just fighting for the sake of fighting. For example, one of the series mentioned in the article above is Cardcaptors, the American version of Card Captor Sakura. In the series, two children, Sakura and Li, are trying to recapture all of the Clow Cards which have escaped. Mei Ling tries to help her cousin Li whom she really likes, but she is fighting one of the cards when she is thrown against a wall.