Beating your wife? I could not see as a cultural thing.

That's kind of exactly my point, though. I see claiming being loud and inconsiderate to others as people practicing their culture to be just as disingenuous an argument as saying wife-beating is a part of Irish culture that just has to be accepted. It's just brought out to defend bad behavior, often with the implication that if you continue to criticize said behavior, you're automatically in the wrong, having revealed yourself as bigoted against whatever group you're criticizing.