the reason football does nothing about it is because these events create controversy, which is then talked about to no end by the fans, managers and media, which keeps football in the spotlight, which makes it more money...
Football's problems could be stamped out easily. If they really wanted to get rid of diving, they would cite players every time it happened and give them lengthy bans. If they really wanted to introduce video replays for goals and penalty incidents, they could quite easily. If they really wanted to stop players behaving so appallingly towards the referee, they would follow rugby's lead and discipline anyone who isn't the captain for even talking to the referee. If they really cared about racism, UEFA would start punishing clubs far more harshly than a few £000 here and there.
As it is, your average man doesn't think of these things and naturally follows the headlines and drama in the same way they'll follow the goals, in the same way X Factor is watched as much for the cheesy moments and Cowell put-downs as it is for the singers. 21st Century opiates of the masses.