u/Just-Library4280 reminded me that abusers can specifically go after someone who is flawed or who has made bad choices. Not only can they use that as a method of control (through shaming and emotional abuse) but they can use that person’s ‘badness’ as cover for abusing them.
For example, if a victim was an addict, and harmed others while they were actively addicted, their family and social circle may be less likely to believe them if they try to tell others about the abuse. (Or they may even see it as a kind of karma.)
A victim’s goodness can launder the abuser’s reputation, and a victim’s ‘badness’ can ‘justify’ the abuse or hide it, or be used as leverage against the victim. (The irony of course being that a bad bad person isn’t usually vulnerable to that kind of manipulation because they don’t care.) An abuser can even use a victim’s flaws or ‘badness’ to prove what a good person they are.