Paired with an obsessive work ethic in the studio.
If it's only obsession in the studio, things come out dry, uninspired. If there's no surge of energy running through your bones when making the music, why would anyone else feel anything? Mixing and the music sounding "professional" is completely secondary. Even detrimental a lot of the time, to be honest.
Applies to many other things than music as well. I don't any great technology comes out and about without that loop, either.