Why for Suns.
Rebuilding team trying to get back into contention. A core of Beasley, Harden, Dragic, Kieff and Bynum(assuming all play up to their potential) would keep us in the top 4 year in year out.
Why for Lakers.
This is a no brainier. They want D12 and will do probably anything to get him without having to trade Kobe. Also Jamison/Frye rotation at the 4 spreads the floor even more for Nash to work the pick-n-roll with D12 as well as provide more room for Kobe to play ISO.
Why for Thunder.
It is no secret that they have a tough decision to make choosing Harden or Ibaka. This is one way to let Harden go to a place he likes while getting something in return. Gortat will give them the one thing they lack which is a player who can play with his back to the basket and give them some easy points. J-rich is a stop gap to make up for the offensive production loss from letting Harden go.
Obviously nohere knows how to read. Suns take Bynum without commitment from him which is what stopped the Dwight for Bynum swap. With D12 in LA the offense will change no need for Pau also the Lakers have a 2-3 year period where they are top 3 team in the NBA. After those 2-3 years they have tons of cap space with an expiring Nash, Frye, Kobe, Hedo and D12 locked in long term. Jrich maybe washed up but all the thunder need is for him to hit 3's and Gortat>>>>>perkins offensively but defensively Gortat</Perkins overall they get better. The magic don't want to be the Bobcats they keep Gasol and Perkins as their frontcourt and then have bunch of cap and picks to stay relevant while they retool.