D'Antoni isn't doing a good job, he's doing less of a bad job, there's a big difference.
Before he was trying to force his Steve Nash offense on the team, which was horrible and resulted in all of those losses and a 10th seed. Then after the team meeting in Memphis, probably some harsh words from management, and Kobe deciding to not give a [expletive] anymore and go ape[expletive] up until his injury, he decided to just let Kobe do it all which then allowed Nash to become more of a role player/3 point threat and subsequently Dwight could get more involved in the offense through a 2 man game.
Good coaching would be implementing a proper offensive system, like the Heat did in 17 games. Right now we're basically paying the man to do nothing (he doesn't even coach defense, those improvements are coming from a healthier Dwight Howard). Kobe's basically running the offense, him and Dwight are the only ones that play defense, and that's about it really. I mean we even saw Kobe drawing up plays at one point during the Indiana game, lol. At that rate might as well let Bickerstaff coach, he did a better job at the free reigns coaching thing anyways.
D'Antoni is still a garbage coach who only looked good in that one system the 2006 Suns ran. We can't recreate that team here, so it's best to send him packing asap.