You could also make the case that trying to build a "dynasty" around one superstar in Amar'e could have been a train wreck as well...cause you know...Kobe won without Shaq and Pau, Dirk has a few rings, LBJ has a few rings, Howard got past Kobe and Pau, Paul Pierce, KG, and Allen all won rings when they tried to get it done by themselves...you know...building a team with one superstar when the last 15 (14 if you want to unfairly overlook the '04 Pistons) champions all got it done with 2 or more stars, or at the very least dominant players at their position (regardless of whether or not they got the media attention and commercials.)
Getting Melo was step one, step two is getting a coach who can utilize what he has and get the very best out of his team and all of his players. You don't have to be on the All-NBA defensive team to play solid team defense...there's not a single NBA squad with 5 starters on that list, but there are multiple squads who have their coaches preach defense and also implement the defensive game plans and their adjustments. MDA does not.
This change is necessary.