As empathetic and understanding as I like to think I am, given the decades of all forms of abuse I've suffered at the hands of people who were supposed to love and support me (only to use and manipulate me), I will NEVER feel sorry for a narcissist. Certainly not my mother and no my ex-husband or the ex's who had narc tendencies. They earned the hell they are in; they treated the people closest to them like garbage. They deserve what they get.
I say this as someone who, again, was abused for most of my life. I was also bullied something awful growing up. And yet I didn't become an abuser, a user, or a bully. Because I knew what it was like to be on the receiving end of that behavior. So, I have a hard time accepting excuses from people who cite horrible experiences and use them as the reason they are abusive or a bully. But again, that is my personal experience.