Oddly enough, I've seen that cause more problems than it's solved.
It's often misinterpreted, in the same way you so conveniently put it, which is then used to justify some pretty awful decisions regarding third-party libraries. I'm convinced that this is the leading cause of bloated software.
Even when used correctly, I've seen some pretty impressive code-contortions to avoid even a very small amount of duplicate code. Sometimes, it's okay to just do a check twice. As long as the code is easy to read and modify, you're fine. Really.
But that's the problem with programming, isn't it? It's little more than wishful thinking and folk-wisdom. That would be okay (it's an art, after all) but too many developers have deluded themselves in to thinking it's more in-line with mathematics or engineering. They've convinced themselves the cute little acronyms they repeat to one another have some objective, rational, basis and must be obeyed at all cost.
It's silly, really.