Racism was common at football matches in the 70’s, but it wasn't viewed in the same way as it is now. The police didn't go around arresting everybody. Same with humour about sexual identity and mother-in-law jokes, acceptable then but taboo now. Times change, and mostly for the better, but should we be judging historical events by today's standards? Sure, you can say it was wrong, but our social history is littered with behaviour that wouldn't be acceptable today.