That they were considered one step below barnyard animals in medieval times is an accurate reflection of their true worth.
I wonder what happend to change things in the minds of so many contemporary normal persons?
Too much booze, I'm guessing.
The difference is that the likes of Sean Penn hit people because they think they're above everybody and can get away with it. Crowe has always been a brawler, especially when drunk. There are a lot of people in this world whose instinct is to settle disputes with violence, and Crowe is one of them. He's definitely not your average Hollywood type, having been quoted as saying he'd only move to L.A. if:
"Australia and New Zealand were swallowed up by a huge tidal wave, if there was a bubonic plague in Europe, and if the continent of Africa disappeared from some Martian attack."