[sciurius]

Because the reflections on the screen bother me.
In the early days, screens were non-reflective and high-contrast. I never understood why it suddenly became necessary to make laptops and monitors (and tablets) glossy. Yes, it gives the impression that the colours are slightly deeper but the reflections make it harder to use under many circumstances. When I put my laptop on my lap, most I see is the reflection of my shirt.

But probably it's also a matter of taste.