My boss is like that, he abuses cut-and-paste to the exclusion of proper factoring. The code is sometimes comical. He does it for the exact same reason, he wants to move on to testing/fixing/improving, rather than spending a lot of time dreaming-about-how-it-ought-to-be.
Sometimes, maybe 3 or 4 times in the decade that I've worked with him, I have needed to do a major re-factoring just to be able to shoe-horn in a new feature. He is glad I'm here to do that, because he doesn't enjoy re-factoring. I'm glad he's there to do his part, though, because a lot of times he can throw out a big *working* piece of garbage in just a few days, while I would still be arguing with myself about where to start.
The machine works. Therefore, I cannot point to any component that is broken. The machine works.
So I enjoy this, I look at all of the numerous insurmountable customer problems that we have dispatched over the years together, and it is beautiful to me. I love my boss.
That's my advice to you: learn to love this guy, to think of his foolish shortcuts and disorder as unique tools that a unique person uses to solve the problems in front of him. Consider it "local flavor." If you're being hauled up in front of management and they're blaming you for his bugs, that's one thing. But if the machine works, learn to love it. If you can't love it, quit programming and go into a less creative field.