I agree with you in general, but I think a better rule would be to almost never rewrite code. I know that everyone thinks their predecessor was an idiot. And I

I agree with you in general, but I think a better rule would be to almost never rewrite code. I know that everyone thinks their predecessor was an idiot. And I agree that full rewrites are usually a bad idea. But sometimes, the predecessor genuinely was an idiot, and the code really is that bad. If the use cases and inputs and desired outputs are well documented enough, a full rewrite can be the right choice. It depends on the size of the system, too. A full rewrite of something as complex as Netscape is asking for trouble. If it's something that can be rewritten in a day, or even a few weeks, it might okay to go ahead and do it. Of course, by the time you've got enough experience to accurately estimate how long a rewrite will take, you've probably got enough experience to just refactor the old code without going insane.