It is for two reasons: - It lets wireless through. - it’s design for the showroom, not at home. A plastic back would be better on most parameters. Lighter, st

It is for two reasons: - It lets wireless through. - it’s design for the showroom, not at home. A plastic back would be better on most parameters. Lighter, sturdier and better grip. But it lacks _luster_ and doesn’t feel or look premium. The glass back is great for the showroom. Not as great once you get home and start using it.