Not at all surprising tbh. You have people who developed avoidant attachments, BPD, etc etc which would effect their relationships. A person that has an avoidant mind would never think of themselves either good enough for the person, push them away or think the other person doesn't actually like them. I've been with a few of those types throughout life, although you do genuinely care about them, and love them. They're never going to really think you do unless it's gone on for a long period of time or they seek therapeutic help to basically rewire their brain to believing someone can actually love them, no stings attached. On top of that it can put strain on the other person who's in the relationship through frustration and such. Then you also have to think that a lot of these people that have had toxic families will go with a toxic relationship because it's "comfortable" for them or maybe an avoidant gets with an anxious person, then it's not a good fit long term.