Totally understandable. I do feel sorry for people who haven’t figured out healthy ways of relating by adulthood, because we don’t all have good role models in life — but truly it’s not the job of their victims (and I’m using that term loosely here) to teach them how to behave. If somebody is behaving abusively/toxically and others want to exclude them because of it, that’s their prerogative; nobody has an obligation to continue enduring shitty treatment in the hopes that the person dishing out that treatment will eventually change.