Both legitimately matter.
Look, playing dirty is disrespectful to your opponents as people. But like i said earlier, disrespect is not universally a bad thing. In the context of the game at the time you’re referring to, not showing your opponents physical respect was a big part of accomplishing your goals. It was a different time and guess what? That DOES excuse the behavior of the people who were brought up in it. Applying modern standards of morality to a past with different standards of morality doesn’t do anyone any good. I don’t think anyone would claim that the way Messier played wasn’t disrespectful to his opponents well-being. The question is more whether or not such a disrespect can really be considered reprehensible.
I don't want to take this in a bad direction but politically we're applying modern standards of morality to the 1400s and the 1800s and that's seen as normal. I normally disagree with that myself, but 1996 wasn't that long ago.