There is this old article that I wanted to discuss for a while and now is the time. If you'd rather say technical dept user story instead of refactoring that is ok. The logic applies to both.
Ron Jeffries explains very well in this article why a system with bad code is bad and what often happen as the system evolves. More importantly he points out what does not happen. I agree with his observation that large refactorings typically do not achieve the desired goal.
The article emphasizes on that cleaning up bad code should just be part of your every day work. When faced with bad code always push through and clean the code up. You will likely be using that same code soon again and will be glad that you cleaned it up rather than worked around it.