With a matte screen you have your thin matte layer directly over the screen. The matte layer itself offers no protection. So if something hits a little bit too hard against the screen, your screen will look like this: http://goo.gl/qSQxl

Cheap glossy screens have exactly the same issue, but more expensive glossy screens such as the ones in Apple's Macbooks or Lenovo's X1 laptop are basically a glass board right in front of the screen. So they are much more resistant against scratches and against other types of physical abuse.