Boolean Operations - Why the fuzzy result after union of 2 objects? I am trying to join this cube.



With this cube with a Boolean Union modifier.


The result is always this fuzziness in the final mesh.  WHY? 
I have checked for correct face orientation and Scale and Rotation.

 

Here is a file upload and screenshot of the Boolean as requested.





Below is a  successful joining of 2 intersected objects without fuzziness as I explained below.
You need to hide object used in Boolean Union operation.
As for now you have "two" objects in one place.

Remember to hide it also for render, or apply Boolean and remove it completely.