I think it's natural for many teams to become complacent, especially as they're dealing with injuries or are simply tired. But, it's certainly not a best practice. It's what separates a team that wins 50-ish games from a team that wins 60.
Yes, I feel that it's what separates the good teams, and players, from the great ones. That's why the likes of Jordan, Bird and Kobe were as great as they were - they never took nights off. They were able to elevate their performance pretty much every time they got on the court. Not everyone can do that. How many of us have made a genuine effort to watch every single Celtics game, no matter what we had planned? It's not easy to maintain that level of focus night in, night out, over the course of an entire season. I can understand if this team gets bored. But, it's what separates the good from the great.
And that's one of the coach's primary jobs, over and ahead of any in game management or timeouts that they need to do - is to keep everyone pulling on the oars in harmony so that the boat continues on its path to its destination. That's what I'm judging Joe Mazz on, ultimately - how well prepared this team is come playoff time.