I don't know. If he was running that system with Durant and Curry instead of Harden and Paul, you might have a different outlook. His system is definitely more prone to upsets given its heavy reliance on the 3 point shot, but I think their lack of winning is much more on the players in the system, then the system itself. I mean it isn't like Harden or Paul had any real success before D'Antoni. In fact, they were both known as playoff chokers (especially Paul) before ever stepping foot in D'Antoni's system.
Kings beat Rockets with last second 3 by Bialicza. Wow.
Got upset by SAC then got denied by the NBA on their appeal.
D'Antoni will never win a championship.
His system is not suited for the playoffs.
Remember the Phoenix Suns of the early 2000s?
That team had an MVP Steve Nash, The Matrix, and Amare.
They won a lot of games, 60 games even, but they always end up failing in the playoffs.
The playoffs is different.
That fast paced offense D'Antoni runs only works in the regular season.
In the playoffs, the game slows down, every possession counts.
What's worse is D'Antoni's teams always played poor defense.