1: The Pelicans had AD for years and did a shit job building around him. Their future now is rosier w/out him than it was with him. I think the cause and effect here is ass backwards. Milw acquired a star like AD in a secondary market and has not had a problem building around him. AD is not a villain nor is the system: the Pelicans have had crappy management and have paid the price. Indeed, that bad management failed to trade AD in what clearly would have been a very good deal due, simply, to spite. They got a competent GM and, voila, they make that trade (or a similar one) and...the rebuild is on. Management is key....
So, no, the "only loser" is not some idea of "owning a person". The harmed party need not be a single person or team, it can be the league and viewing public at large.
2: The NBA is more popular than ever so I fail to see how it as an entity is suffering, either.
3: The teams in last year's finals were Toronto, Milw, GS (Oakland or the Bay Area, in general), and Portland. None of those are giant markets (though the Bay Area is pretty rich). For next year. there are 6 excellent teams in the West (including Portland and Utah) and two in the East (including Milw) -- plenty of winning to go around/plenty of competitive balance.
4: The two NYC teams have been awful for years and 1 of the L.A. teams has been awful and the other just kinda good. Both the Clippers and Nets have had exemplary rebuilds that have relied little on their being in major markets. The Lakers have been sort of dysfunctional and have paid they price -- they are, if memory serves, the losing-est team in the NBA over the last 6 years. In re LeBron wanting to sign with them due to them being the Lakers (I guess), clearly they took advantage of both their brand and their city in a way that, say, Charlotte couldn't. But in the big picture, even with Magic in charge they've fucked up lots of little things but mostly did the big things right in re clearing cap space to build around LeBron. The Knicks have been a total shit show and...they lose and lose and lose.
I'm not saying being in L.A. or NY or Miami (another marquee city not doing all that great) isn't an advantage -- clearly it is and clearly that has benefited the Lakers, specifically. But I'm failing to see a major issue here. Compared to the years when the Lakers and Celtics were seemingly winning every year, there's far, far more balance in the NBA, the league is much healthier, and players have more control of their own destinies which I think is just.