I think it was sustainable, but it's kinda beside the point to me.
Our front office was infatuated with how the Hawks, Warriors, Spurs and other teams play. They view that as where the game will be in 2-4 years. It's not just the pace, it was the limited 3 point attempts we were taking. They fired Malone because they believed this would be a really good team by this time in 2017 but they would be held back by an antiquated offense.
They put this team so far in a ditch that this time in 2017, DMC will either be gone or about to be traded. I'm going out on a limb and saying that's going to be more of a problem for this franchise than the pace and volume of three pointers we shoot in 2018.
And the notion that this error is in our rear view is false. You've got a GM and owner that are covered in tar from their own incompetence. If the GM isn't fired in two months, he's on his last leg. The owner wants to win now, needs to get right with the fans, and will probably loose money in 16-17 if things don't get a lot better next year (even as he opens a new arena, because we no longer get revenue sharing and the cap will be 90 million). They also want to appease Cousins. This is when people do really stupid things. For example, folks are super hot to trade our 2015 pick for help now. Those 2015 and 2016 picks are insanely valuable because: player salaries are going to explode when the cap goes up; the rookie scale is locked for 2015-16; and the rookie scale will probably be adjusted upward to reflect cap bump when the lockout ends. The already coveted rookie deals, are now about 30% more valuable because the cap will jump well before they end. So if Denver wants to give us Lawson for # 6, fine. But the notion of just trading the pick for some help now could be a really horrible trade. But if you are GM about to be fired and an owner on the verge of being a pariah, sure why not.
If you are in the "hey it's over, lets move on" camp, I get it. But, I think the pressure to hastily fix this self inflicted wound may lead to some really questionable moves this summer.