This post perfectly encapsulates the no-win situation the producers are in. Have a "traditional" or "villain" death for Cersi, where she gets slain by Dany, Arya, or Jon, and I guarantee that there will be dozens of posts here that are variations on the theme of "OMG! What a cliché death, of course the hero kills the villain, lazy writing D&D! GRRM would never have done that, he'd give us a twist!" ...OTOH, they kill Cersi in a non-traditional way and we get posts like this about how unsatisfying her death was.
I was pretty happy with her death. She's a bully who when faced with her imminent demise and no more get-out-of-jail-free cards, broke the facade of toughness she put on and became the insecure, quivering mass we suspected her to be underneath. Plus there was the irony of her world literally crumbling around her, and they literally dropped the Red Keep - the embodiment of everything she worked towards - on her head. It was that which she sought, her hubris that killed her off.
Jamie dying with her was a good conclusion to his arc. If he had turned "hero," and gone to the good side everyone here would be bitching about traditionalism and hero's journey, etc. He had a slight turn toward the good with his battle for the living, but in the end couldn't deny himself, and went back to his comfort zone in Cersi. It rang true for me because it's his weakness, and ultimately led to his death.