Comment by Zibulon

Maybe that's too short sighted. Constantly rewriting code has a big cost. A huge cost actually. I see it at my work everyday: there is a pervasive (fashionable?) attitude that no code lives more than 3 years, and we have incessant "migrations" to new and better systems. You wouldn't believe how costly those migrations are, including through losing good people who don't want to suffer through them (and I am sympathetic to their plight, it's really horrible)...