when you add an object in the 3D view it will be added as per the view angles
and not the global system X-Y-Z axis!
is this normal 
?
Note: in top-front-side view it is already following the global system axis
Tanks & Salutations
Yes this is normal for Blender. It is generally wise to add things in top view to keep everything aligned the same.
After creating the object, press Alt-R in object mode to clear any rotation.
why ?
-to do what ?
why ?
-to do what ?
I assumed you wanted your object to be following the Global Orientation System. If you have added an object with a certain view angle you can reotientate the object to follow the Global Orientation System by pressing Alt-R in object mode.