If the center aperture on the front spoiler is not used (except in tip) why are guys mounting their plates up at the upper radius of the front bumper?

Putting an ugly tag at that location seems so distracting to the great curves of the front of the car.

Why not stick the plate lower and in the recess if possible?

Does the car look like a frog with buck teeth or something you put it lower?

Is there some legal thing in Europe?

I know the USA could care less where it is, as long as it is vertical and visible from front of car.