I think it's a hard sell that Miller needs 10 games off because of his problem with Petey and it's Petey that needs to grow up.
We're all speculating here but there's always going to be different personalities in the locker room. The key is that our players need to be professional. People brought up Kobe and Shaq well there was at least one star realizing that he needs to work with the other in order to win. It's not like Jordan, Pippen, and Rodman were great friends. Regardless that's basketball.
There's going to be cliques. We know Bieksa, Kes, and Burrows were close friends. Were these three close with the Sedins? There's no evidence of that.
If I have to guess and speculate, Miller is more likely to clash with other players. We've seen him clash with Schenn and there's the Delia accident. Does that mean Miller is a locker room cancer? Not necessarily. Maybe he really is just an intense guy who is there to work and not necessarily to make friends. Cup winners always have one guy in the locker room who is more of an emotional leader.
Petey doesn't need to lead in the locker room. He needs to lead on the ice. Hughes is the captain. It's part of his job to mediate the personalities in the locker room.
If there is an issue in the locker room then the team needs to come up with solutions. if Miller's abrasiveness is a bit too abrasive he needs to tone it down. If Petey is letting outside forces affect his play then he needs to learn to not let things get to him. So saying Petey needs to grow up is similar to telling someone they need to toughen up even if they mean "mentally."
The reality is that is hockey locker rooms isn't this inclusive safe space. The hazing might be gone and rookies aren't carrying everyone's bags anymore but it's still a room full of smelly testosterone. He's not going to get much support from Tocchet, Foote, and Rutherford either.
I'm not saying one is wrong as I don't know the details. A lot of it is perspective and upbringing similar to politics. Like if you ask Russian hockey players that grew up in the Soviet era about NHL coaches with the reputation of being a meanie they often don't have anything bad to say. Verbal abuse is something they just shrug off.