To explain it in a programer terms, it's like refactoring a code that works. Even if it's written in a decent style, event if it's bug free and fully maintainable, many developers (and I'd say any good developer) will still feel the strong urge to re-style the code, to optimize the logic to use a more elegant loop, better testing or something. People just enjoy building beautiful things they are proud of and IMHO willingness to take that extra care of details is certainly not a bad thing for any creative professional... the company might loose a few man/hours here and there because of it, but in a bigger picture it will certainly benefit from the overal quality of work done in such a manner...