[dannypgh]

My rule is be skeptical of anyone proposing a rewrite who doesn't fully understand the existing system, to such depth that they would feel comfortable refactoring it. Which means anytime someone says "we want to rewrite it because refactoring it is too hard" I tend to not believe them.

There are times when rewrites are less total work, but they're hardly ever "easier" when you account for the cognitive load of making sure the requirements of the rewrite are being accurately captured. Maybe there's an exception if you know the requirements have been drastically simplified, but I doubt that's practically useful.