You obviously did not read my post. Okafor posted 17 and 7 on a 76ers team that won 10 games all year. That tells you he had talent and was willing to work to succeed.
The bottom line is Okafor was a victim of bad timing, injuries and poor development. Hinkie was forced to pick him as the first step toward his firing after Okafor's rookie year and the new GM, BC, along with his father JC, did not believe Okafor could stay healthy and fit their vision. They buried him on the bench, stalling his development until they eventually dumped him for nothing.
BC also publicly questioned Okafor which, along with the benching, effectively told any team the 76ers did not value him and he would be available soon for nothing. They let Okafor dangle in the wind for a long time which was really bad management. Why would any team pony up anything when they did not have to?
The Nets and Mavs suck and are largely disinterested in or incapable of developing talent or building a winning team. They are either rebuilding as all NBA teams have to (by sucking badly) or terrible organizations. Okafor and Noel are warm bodies to them until they can get rid of them for cap relief.
Again, this is why the NBA needs a real minor league system. Both Noel and Okafor are still young and could help some team. Hopefully, they'll get another chance somewhere else soon.