I have had people tell me that I should not ever change modules once they are verified to work the way we need them, even during changes to systems for version+

I have had people tell me that I should not ever change modules once they are verified to work the way we need them, even during changes to systems for version++. They claim "If it ain't broke...". Such thinking is itself broken, I consider refactoring and adding functionality to keep up w/ specs to be fixing brokenness. The alternative is layers of cruft which is fragile and smelly, but preserves some core that is no longer adequate.