More times than not, I've found rewriting code leads to more problems than fixing some trivial error. Some small bug in the code is not necessarily a symptom of a horrible design that will destroy your project.

I don't know about the random guy who wrote this article or his experiences, but I rarely find myself with a few weeks to throw away rewriting code that works.

I submit to you http://www.c2.com/cgi/wiki?RewriteCodeFromScratch for a more reasonable and comprehensive discussion of the topic.