Since the OP mentioned Marty McSorley, this is an interesting interview.
I like that interview because McSorley talks not only about the fighting, but how he is bluntly unapologetic about the occasional goonery and dirty cheap shot. That kind of violence could sometimes benefit the team if used as a retaliation or intimidation.
Even after that totally unnecessary and dumb/careless Brashear-incident, I would not classify McSorley as a "psychopath" (career wise, Marty was a decent skilled player, who just took his enforcer role very seriously) but I guess some disagree.
McSorley's comments here will be incomprehensible to today's young'uns, but of course back in the late-80s it was still the Wild West in terms of refereeing and League suspensions/penalties.
In retrospect, it's now clear that the NHL was going through a change from around the late-70s through the mid-90s when salaries were rising for stars, and the distance between superstars and grunts was greater than ever, and yet the level of accountability from referees and League officials was still the same as in the 1950s. In other words, it was old-school officiating with modern-era sports' stars, and the result was that players like McSorely were essential for teams.
In his own unique way, McSorely comments do make a kind of sense. He's saying that, in that era, it was wrong when a borderline NHL-er was taking shots at a Gretzky or whomever, and, since the NHL didn't do anything to prevent that, players like McSorley had to.
That said, because he was forced by job-duty to play on that edge all the time, McSorley did cross the line a few too many times and contributed to the League's image problems in that era. (I personally don't think the Brashear thing was a big deal; McSorely's worst moment was the spear to Mike Bullard in the 1988 playoffs.)
Anyway, as I explained earlier, I don't miss goonery at all, but I also don't blame guys like McSorley for the craziness that sometimes occurred. Those guys had an important job and did it. I blame the NHL for being so damn slow to keep up with the times and for not even bothering to enforce rules to protect their own superstars. (Of course today, in knee-jerk fashion, the NHL has gone too far in the other direction and NHL hockey now resembles ringette.)