Mark pointed to the fact that Denmark's history with slavery doesn't go as far back, didn't grow up around decades of racial oppression, and went largely unexposed to the deep and systemic poverty that often plagues minority communities. These were his reasons for a cultural disconnect from such a powerful word. It became "just another foreign bad word to us, no different than fuck or shit."
"My point is," he said, "I think it would be foolish of me to say that I'd ever be capable of fully understanding the weight of the word when I've never truly experienced these things. That is probably why my gut doesn't feel the same way when I hear/say that word as yours does."
That's rationalization, not an explanation. You should know better, and so should PewDiePie.
As I said on Twitter, the idea that you "accidentally" say slurs of any sort while streaming to thousands of people just doesn't just happen. PewDiePie isn't an amateur; he's a professional who makes millions of dollars each year while playing and streaming games, and one who's routinely got in trouble for trotting out botched attempts at anti-political correctness satire as humor. He knows what it means to perform for an audience, a tightrope of playing a character and yourself. But instinctual moments like this can reveal the ugliest parts of yourself. If, "in a heated moment," you use a racial slur, that's part of who you are.
In replacing "nigger" with "asshole," PewDiePie reveals his own disgusting, if rationale, logic: the two words hold equal weight, there's just one you're not supposed to say in public. Oops!
The thing is, it is possible to say something racist without being a racist, but just because your mouth shits it out without fully internalizing the ramifications and historical weight of the word, doesn't excuse those actions. It's your responsibility to do the hard work of recognizing why you chose to use that hateful world, why it's the one that came to mind in that moment.
It's true that racial slurs of all kinds and other hateful words are standard fare when playing online games, or surfing the Internet more generally. It's part of a mass normalization of ugly rhetoric, a cultural shift where we've become numb to words that would once make us wince, a decades-long form of cultural astroturfing to make racism seem normal in online spaces, a way of using shitposting to make sure spaces remain unsafe for people who aren't like them.
PewDiePie is a public figure who should know better—who does know better—and by acting this way, contributed to the normalization of a word that should hang heavy, a word that should remind us of the great historical injustices the world has served—continues to serve.