It's DC's right to fire people who think for themselves. People who think for themselves and have opinions can potentially work counter to the Greater Goal. It's far easier to edit writers who are passive, take a lot of bullshit, and are OK about having their stories and characters fucked with by people who don't know shit about storytelling.
Wow. DC took the writer of the legendary Justice League cartoon – which truly, in my circles, are considered legendary episodes – and couldn't even fucking work with him in a satisfactory manner. Whose fault is that? Is that Dwayne's fault? Obviously, Dwayne knew how to write Justice League stories. That point is not in question.
But Dwayne was and is an independent thinker, someone devoted to the quality of the story rather than just being a cog in a machine. It boils down to that, and that was something that in the end, some people in power absolutely could not process.
"It is a far, far better thing that I do, than I have ever done; it is a far, far better rest that I go to, than I have ever known."