It does look like a lot of extra work, but actually, it is not as this is actually the indispensable of software development.
Basically, once a developer runs Code Auditor and FxCop a few times they get to know the rules pretty well. After that, it’s no longer an issue of extra cleanup work – you just code correctly to start with. You’re painting the same wall – just that you’re using red paint instead of blue paint.