I think, as a rule of thumb, it's healthy for most people to have experience with completely cutting off and ostracizing at least one shitbag in their life. Even better if the shitbag is sorry and wants to stick around.

Forgiveness is important. But I think what many of us have today is a sort of societally enforced quasi-forgiveness which states something like "even if this person has transgresseed against you, you must let it go and continue to work with them in a natural manner."

As a result we can't really forgive (or not forgive) fully. Both acts are shot through with anger and ambivalence. Because there's a societally enforced expectation, a lot of the time the offending party doesn't feel like they have to actually take their transgression seriously. Their repentance is just a token gesture intended to trigger a societally enforced forgiveness script.

And because there's a societally enforced expectation for forgiveness, many people feel a subtle push of towards reconciliation, even when their body is screaming at a visceral level "oh fuck no this person is never to be allowed close again."

Since the weight of expectations pushes us towards reconciliation, not forgiving someone is a very angry experience, because we have to constantly summon the emotion as a defense mechanism against the pressure (both internal and external) to let them close again.

That was the case for me. I was finally able to resolve my anger when I accepted that I had an inalienable right to cut someone from my life. People do it all the time; we select those who we want to associate with based on often shallow criteria like looks, status, taste in music, or a general sense of whether or not they "fit."

So it doesn't make sense to feel ambivalent about cutting someone out based on much stronger criteria like "this person betrayed me," just because they were closer for a while.

I'm not advocating that we ostracize people close to us for frivolous reasons. I'm just saying that forgiveness is really only meaningful when we start from the understanding that everyone has an inalienable right to decide not to forgive.