Why a screen overlay when scratched even during installation

Unfortunately, I must say that I am quite disappointed with this film.
The installation designed hard time, since the film is actually the same size as the display itself. Take a few attempts, but eventually they have been on it and removed the bubbles to instructions.
But when I had then held the film up to the light, I was already disappointed:
She alone by the Assembly, mind only with the supplied tool, even minor scratches.
I think therefore the film is unfortunately too soft and very disappointed.