When someone refuses to acknowledge and heal their pain they develop toxic behavioural patterns because they perpetuate the patterns that caused the pain they are in denial of.
So while we can empathize with someone’s core wounds, this can’t be used as an excuse for their toxic behaviours. Hurt people don’t hurt people. There are plenty of hurt people who are too conscientious and sensitive to inflict the pain that they feel.
Toxic people hurt people.