Cool Motive, Still A Crime/Playing With

Basic Trope: A villain's backstory is brushed off because of their crimes.
 * Straight: A hero dismisses the villain's sob story.
 * Exaggerated: "Sure your mother may have tried to drown you when you were a child and beat you black and blue, but it does not excuse you for sending her to a nursing home."
 * Downplayed: The hero is sympathetic to the villain but is nevertheless determined to stop them.
 * Justified: The villain has crossed the Moral Event Horizon so many times, their backstory doesn't even come close to to making them sympathetic.
 * Inverted: The hero takes pity on the villain knowing what they went through and tries to get them help.
 * Subverted: It seems the villain's sob story will earn them pity and the hero releases them.
 * Double Subverted: Until they cross a line they can never come back from.
 * Parodied: "So what if you were under Demonic Possession and had no control over your actions, you still committed the crime.
 * Zig Zagged: The hero goes from dismissing the villain's backstory to wanting to pity the villain only for the villain to keep committing worse crimes.
 * Averted: The villain doesn't have a sad backstory at all and is only evil for fun.
 * Enforced: "What happened to you is sad, but it doesn't excuse your crimes."
 * Lampshaded: "Good on you for not getting sentimental over that sob story."
 * Invoked: "We went through what you did and we didn't turn to crime."
 * Exploited: "The villain's actions are indeed justified, but he's still a criminal so let's use this trope against them."
 * Defied: "No wonder why you turned to crime?"
 * Discussed: "I wish I knew why he turned to crime but at the end of the day, it doesn't excuse his massacre."
 * Conversed: "Oh boy, the sob story, big deal.