As others have noted, this is merely a testament to the kind of elite player Hughes is.
To use a Tier List analogy, Canucks have had a lot of B Tier d-men. You could even argue that some of them were A Tier for some seasons (but not their whole careers). And they've been flat-out unlucky in a lot of cases (Ohlund, Salo, Reinhart plagued by injuries, Bourdon fatal accident, etc).
But Hughes is S Tier. A tier so special, rare, and unique that the only d-men in it are HoF/Norris winners. And he's an offensive d-man which is even more rare. He's putting up some gaudy numbers. The kind of numbers we haven't seen from d-men since the 80s. He's on pace for a 100-pt season, a feat so rare only six guys have done it (Orr (6), Coffey (5), Potvin, MacInnis, Leetch, Karlsson).
And we are blessed to be living in an age where Hughes isn't the only offensive d-man. Makar, Josi, Hedman, Fox, Dahlin, are all ppg d-men, knocking on the door of elite status.
But we all know the true measure of greatness isn't one elite season. It's having a whole career of elite seasons.