Let me unpack this excellent phrase.
If we compromise anything, like those people who were suggesting after the TLM, (not in Dublin, but another place,) to take an illegal position, my conscience would become confused. One cannot have a keen conscience and muck about.
Two, confusion leads to more sin, like those who do illegal work not declaring income tax and so on. More sin piles on to more sin. Lying, cheating, stealing and so on.....
Three, corruption leads to collapse, which for a person is the loss of the soul and for a Catholic institution, a collapse into heresy and scandal.
Simple, really.