Giving the NBA that type of power would essentially allow them to choose where players go opposed to players choosing their destinations. The league would be able to load up the big market teams that bring in the big dollar revenue and forget about the little guy. The small market teams would suffer as result.
There are too many issues involved with contracting. The league can send players anywhere with bias, they can also have a big standing in determining the status and existence of other players. Teams should be able to choose the best players that they can and go from there, contracts just add more issues.
The approach of having players on contracts can be bias, and purely unfair to other players, such as those who refuse to be contracted. Players should join teams without having legal indoctrination determining the status and existence of concurring players and money laundering as well. Teams should choose the best players, and tying down people to contracts is never the best.
I am a big fan of small teams (of the "underdog" so to speak). The NBA contract will end up putting the smallest teams out of business. The pro-contract argument is they are losing money. So? Fix it without cutting things. I guess I don't have much patience for really rich organizations complaining about losing money and threatening to cut jobs to fix it.