Well, Reality has a point - if the other teams get together, they can force the hand of the Lakers and of Kobe.
Of course, that's called collusion. Anyone remember that saga in pro baseball?
But sign-and-trades aren't always as helpful as people think. Often, they are just about MONEY. Grant Hill essentially screwed Orlando by doing the sign-and-trade, depleting the team he was going to of talent he could have used.
There comes a point when, if you're a competitive person, what you're doing to the team has to be more important than the cash you bank. The big problem is that with almost all of the competitve teams, they're over the cap. And it's rare a top-notch player wants to go to a team that isn't competitive.