Once a Priest...
A family member is scandalized by a priest who left the priesthood but who continues to celebrate the sacraments, specifically the Eucharist. I don't know his canonical status, but it's not a public Mass. I am not scandalized because I believe ordination is life-altering. It's not simply a piece of paper, just as marriage is a sacrament and not paperwork.
Just as once someone is validly married and then gets a divorce and re-marries, the remarriage occurs only in the eyes of the world. It doesn't change the underlying validity or permanence of the first marriage in God's eyes, the eyes that count.
I think in modern democracies people are allergic to differences, let alone differences that can't be seen with the naked eye. But the Church is not a club or a bowling league. The rules are enforced and the powers which flow are by and from God, not from its members.
The ordination ceremony quite clearly states that "you are a priest forever". It is a mystery of faith that he is not the same after ordination than he is before, but too often in our prosaic non-metaphysical world we don't recognize that. I love the sense of permanency.