As a kid, you maybe went camping with the boy scouts. One of the important camping rules is to always leave the camp site cleaner than you found it, even if you have to clean up someone else's mess!
The same thing is true for code. So if you are refactoring, debugging, … and you find some messy code, always clean up(especially if the code was written by the lead architect :-). In time this will make an ugly code base better and more developer friendly.