You're sitting in a meeting, contemplating the code that your team has been working on for the last couple of years. You've come to the decision that the best thing you can do now is to throw away all that code, and rebuild on a totally new architecture. How does that make you feel about that doomed code, about the time you spent working on it, about the decisions you made all that time ago?
For many people throwing away a code base is a sign of failure, perhaps understandable given the inherent exploratory nature of software development, but still failure.
But often the best code you can write now is code you'll discard in a couple of years time.