badtic - You are dead wrong. The fluid moves a lot.
As I have noted before, a number of cars have been 'fixed' with turkey baster flushes. Going from jet black to amber after a few weeks of treatment. And wheel cylinder problems were fixed.
It mixes due to movement and heat. Sure, not as good as a flush, But it does work and help.
Moisture and dirt are removed, boiling point goes up, wear goes down. Parts can get freed up, and ABS can work better, as they are sensitive to debris.
Who wold not want clean brake fluid?