Let's face it: Gemma was rotten to the core. After everything she did, she was served her just reward at the end.
However, when Nero (Jimmy Smits) came into her life, it opened up another dynamic and different side to her. We saw the potential for Gemma to have a happily
Much like Tara tried to act as a moral compass for Jax, Nero did the same for Gemma. He suffered for her, as he was pulled into her crazy and violent world.
After all the emotional (and physical) trauma, it was surprising to see Nero spared from the same fate as Gemma.
Still, he didn't deserve to go down in flames, as his light was absolutely necessary on this show.