Appropriate guilt is the soul’s natural response to choosing to do something wrong. Shame is humiliation due to the effects of bad acts inflicted on the self either from oneself or others, which diminishes, even slightly, the fullness of personal integrity and dignity.
There are those who claim that redemption in Christ eradicates any and all shame. I question that. Until the resurrection of the body on the last day, we remain diminished by the effects of sin and injustice. Although Christian faithful are ‘bought back’ by Christ and sanctified by the Spirit, our integral perfection is not complete until after all effects of sin are eradicated from our being. Until then, a degree of humiliation, from which the word humility is derived, is appropriate for all, in the form of shame. We are still sinners and remain affected/diminished by sin until fully healed, purged, and glorified at the general resurrection.
Yes, much of the shame people feel is unnecessary and/or inappropriate. Nonetheless, just as there is such a thing as appropriate guilt and appropriate anger, even though wrath is one of the seven deadly sins, there is also appropriate shame, which corresponds to our wounded nature in this life and keeps us humble on our journey.