There’s a dynamic interaction between the borderline individual’s innate predispositions and the traumatic early history they have typically experienced. It’s hard enough for a person who tends to react strongly and erratically, tends to think dialectically, and is prone to mentally splitting unitary realities into polar opposites to get a solid sense of what the world is like and how to deal with it. But when you put such an individual into an environment where there is actually is no safety or consistency, you have a recipe for genuine disaster when it comes to personality formation and solidification.
Make no mistake, all of the defining characteristics of character disturbance (e.g., deficient empathy and conscience, sense of entitlement, penchant for manipulation and impression-management, etc.) are at work in anyone who sexually abuses.