"I don't think you can really take the position and say that person deserves to be punished when he was himself damaged."
Napier stoked controversy when he refused to expel South African priests accused of child abuse after the scandal broke out in 2002.
Francis' predecessor Benedict XVI -- who stunned the world last month when he became the first pope to resign in 700 years -- offered a historic full apology in 2010 for child sex abuse by priests.
But critics said he failed to follow this up by acting against those responsible.
Abuse victims around the world have called on Francis to redouble efforts to ensure that clergy who covered up abuse are held accountable.
Barbara Dorries, from the US-based Survivors Network of those Abused by Priests, told the BBC: "If it is a disease that's fine, but it's also a crime and crimes are punished."
She added: "The bishops and the cardinals have gone to great lengths to cover these crimes to enable the predators to move on, to not be arrested, to keep the secrets within the church."