That is a good article. On the is it the coach's fault or the players' I'd just add:
1) Obviously both.
2) Generally i'm in the camp that coaches get waaay too much credit/blame. Mostly blame: not a fan base in the NBA who doesn't seem to think they are uniquely blessed with a coach unable to correctly time time outs or figure out rotations. That's generally hot air nonsense.
3) I think the Joe M case is different...he's clearly in over his head. Coaching is 2 things: 1) doing whatever ineffable things a coach does to keep a team focused/mentally prepared; and 2) the x an o element.
The 1st of those is nearly impossible to judge except by results. But as the public face of the team Joe M is...I mean, awful. He comes across as a stubborn, insecure control freak during press conferences and count me in the camp that the throwing the clipboard tantrum came across as lame and immature. Not that it's not a tactic that can work, but when the players openly express disrespect for the coach, when he reinforces that disrespect with press conferences that, at best can be termed tone deaf and at worst semi-idiotic, then those tactics won't work. If Pops does it, players will stand to attn. But Mazzulla hasn't earned that respect and seems to be going backwards in that respect. There's been a lot of commentary that the Celtics mental discipline issues pre-date Mazzulla, which is likely true, and that so it's on the players. Of course, it is on the players: but that's the point of a coach: to get players who are underperforming in some way and help get them into the proper mental state. It might partly be on Ime and its certainly on the players, but if the current coach is to earn his pay check he needs to be part of the solution.
The 2nd is also hard to judge as, of course, if Brown plays awful or Rob is injury-affected, it'll make the best coach look bad just as great players can make a bad coach look good. But Joe M's post-game comments make public that he doesn't seem to consider in-game adjustments, that his strategic moves seem random and ill-thought out, but he sticks to them stubbornly, and that he just is not at the level of other coaches we've seen -- from Spoelstra to Malone, Ham, Kerr...we've seen a lot of really great coaching in teh playoffs and one guy sticks out as the exception.