Last time I checked, it's the general manager's responsibility to understand why his superstars are successful and to not piss them off.
Also. Generally speaking. The general manager is supposed to ADD value and not SUBTRACT value which is what they did last off season.
FO really gimped the line up when they let Tanev walk and pissed off a lot of players including Quinn who responded by taking the season off.
This ain't new. FO pissed off the 2011 core after the 1-2-3-4 loss to Hartley and CHiggs responded by getting waived and Vrbata responded by pouting.
When your managers f*** you over, there's usually a response and that response usually isn't oh-boy-im-going-to-work-so-hard-now.
Well, the last time
I checked, it's a player's responsibility to be a professional and not allow higher-level business decisions (even mistakes) to impact their on-ice performance. If Quinn did, in fact, "take the season off" because his defense partner was let go, that says a hell of a lot more about his character than it does management. Personally, I don't think that's the reason his play fell off but, if it is true, it's pathetic. That said, if that is the case, I'm willing to excuse this behavior because he's young and, likely, a bit full of himself. In the real world, you can't just give up because you disagree with managerial decisions.
Above all else, a true "superstar" talent is not reliant on other players to succeed. When a Sidney Crosby has to play with a revolving door of 3rd/4th liners and AHLers, he has a right to be pissed off at his management team (see the Penguins from 2010-2016). But when Quinn Hughes requires another defenseman to babysit his mistakes, so he doesn't fail miserably at his primary role of defending, that's not an excuse to pout to management. And it certainly isn't a reason to write said player a blank cheque.
Hughes has weaknesses and his contract should reflect that.