This seems like a policy change on the NBA's part. I don't think the refs did this on their own, and I don't think the NBA would make a point of doing this if it didn't make a difference to their bottom line somehow.
The thing is that I am not sure how it does. By way of background I will say I have been wanting them to penalize stare downs and mugging for the camera nonsense for a long time. It might add to your enjoyment of the game, it takes away from my enjoyment of it.
I don't think there is inherently anything wrong with players doing this, its just my personal preference. My assumption has always been that I am in the minority on this one, that most people don't care one way or the other about these kinds of celebrations, and that at least as many people like them as dislike them. But now I am not so sure. Perhaps they have some data on viewer preferences that tells them there are people who really don't like it. That would surprise me. I would have thought that everyone who hated the post dunk shenanigans would have stopped watching the NBA long ago. T-ing players up for stare downs and doing their little faux tough guy act after dunks isn't going to bring those people back because they stopped watching. They don't know that this is happening.
But while I find it unlikely that it makes the money, I find it even more unlikely that they would do something like this for any reason other than money. I just can't figure out how it makes them money. I can't believe there are enough people like me who are bothered by this for it to make any kind of real difference. Maybe advertisers are telling them this, but again I have trouble seeing why advertisers would care unless they have data saying that people are tuning out because of post dunk celebrations.
Probably Lebron. His playoff failures early on made me think he was going to top out at something like T-Mac's level. All time great player but not in the realm of people like Jordan, Magic, Bird, Hakeem, Shaq or Duncan (earlier players in this tier too probably but I didnt see them play). Even the victories with the Heat didn't change my mind on him. Just thought he got better teammates who could pick up the slack for him. Looking back that was a mistake but probably because I just hated the heat (Bulls fan). The Cleveland and LA titles (but especially the Cleveland run) changed my mind on him. Doing what he did to beat the Warriors and then hang with them in those others finals, despite already being a little past his physical prime, was amazing.
In the other direction, Vince Carter. If you had asked me in 2000 who was going to be the better player between Vince, Kobe and T-Mac, I would have said Vince. He was a better shooter than either of them, and was stronger than Kobe without giving up anything to him in athleticism (maybe was even more athletic). And in the end its not even close between him and Kobe, and wouldn't be close between him and T-Mac if McGrady hadn't declined early because of injuries.