I would say that the Lakers are a unique entity because Los Angeles is a unique city. The market is fickle and showbiz driven. The organization is under a lot of pressure to keep the franchise relevant and not rebuild for too long a period. Since they are a historic franchise in one of the country's biggest cities, naturally they would use their location as part of their strategy.
They have a lot of fans, but they would lose interest if the team was bad for too long. The weather is always nice in LA. If the Lakers stink people will just get their entertainment from a different source, not necessarily basketball or sports. This is why the Rams moving there hasn't been the automatic slam dunk it should be if you just look at market size/income.
The necessity to trade for a star is lessened now because players have learned to wait for free agency. This discourages teams from unloading too many assets because the risk of the player leaving is too great. The Knicks foolishly traded a bunch of assets for Melo, then didn't have enough talent to surround him with. The Lakers lost Howard for nothing.
When's the last time a superstar player was dealt? One besides Cousins who was dealt because he was a head case? It just doesn't happen much these days.