I think it's too late. I think it already has cost them. I used to watch 8 to 10 games a week. Now, if I watch the Lakers once, that's a lot. Back in the day, if I could have watched more, I would have. Now, I almost have to force myself to watch the NBA. To many commercials, to many interruptions, to many bad calls and just simply horrible play.
Your idea is interesting and at this point, I'd almost be in favor of anything but something that radical, I have my doubts that the league would be able to make that stick.