You’re point still doesn’t hold with the national trend this year re: the NBA so whatever. Attendance and TV revenue is up nationally, but you’re right Dewey Howard ditching that shit storm in Orlando in two years is going to kill interest! I just know it!
But you don't see a difference between now, when the whole superteam thing still has a lot of novelty and intrigue, and five years from now when reality has set in? You have a lot of people tuned in this year to see how it plays out but that could give way to indifference if the same 5 preconceived destination city teams start being the only ones with perennial title aspirations. A couple of small market contenders will be in the mix too but their windows to compete are growing shorter at this point. I see OKC as the exception but that's not enough to keep the other half of the league interested. Teams aren't going to be able to make much hay at the box office if they're only relevant for 2 seasons before Player X wants to go party in Manhattan.
I don't even think we disagree on the needed changes though. They just need to beef up Bird rights on rookie contracts and share more revenue. It's probably all they can do. The product is still great and again, your argument is fine if you're also OK with contracting several teams. I just think this is a bigger problem than you give it credit for.