why micro focus adjustment ?

Well, with the change in the title you show that your own title missed the point...

On top of that: the adjustment takes place in the camera with MA.

It's a matter of priority: as was said before, tolerances are possible on both sides. If all my lenses except one can focus correctly with the camera at hand I'm glad the camera can adjust for the only one that can not. Thank Sony for it's MA

. If almost any lens has the same type of misfocus on the camera at hand you will probably send it in for correction.  Since this is pretty expensive I thank Sony again for MA