This is quite common and pretty harmless. The scratches you see don't go very deep, nor are they very wide. My All-Clad saute pan is nearing 10 years old and has a ton of micro-scratches on the interior. It still performs beautifully.
That said, the scratches can grab onto proteins and cause sticking. However, this is simple to prevent with both oil and proper pan preheating.
When a pan is preheated properly the metal expands, essentially closing all of the micro-scratches. This prevents the proteins from grabbing onto them and getting stuck. You obviously need oil/fat to assist with this as well.
To properly heat a pan to the appropriate temperature I suggest using the water drop method. If you put a cold pan on heat and drip a drop of water onto it, the water will sit there for several seconds then boil away. As the pan gets warmer this will happen more quickly, fizzling away in a second or so. Once the scratches start to close something weird happens.
First, the drop of water will break into a few mini drops which scoot around the pan as they evaporate. This is a sign that you are almost there. When the drop of water stays whole (mostly) and scoots around the pan like a mercury ball, this is the perfect temperature. I the water instantly vaporizes on contact, you've gone way too far and need to let the pan cool down. At this point you should add your oil/fat, swirl it around, and immediately add your food. (Make sure the mercury ball of water is gone before adding oil).
Also note that the mercury-ball phase is definitely too hot for unclarified butter, and may be too hot for some extra-virgin olive oils. They may instantly smoke upon adding.
Again, it's important to have your oil and ingredients in place (mise en place) before you start. It's quite easy to skyrocket past the mercury-ball phase if you have to open your oil, pour, and then season your ingredients.
Silpats and Exopats have a glass fibers (regionally called fiberglass or glass wool, but not candy floss) embedded in them for strength.
The warning not to use them when scratched is because fiber glass does nothing good for a person when ingested, and a scratch may expose it.
Some types of silicone based cookware do not have the fiberglass reinforcement, and so do not have the same issue. These are mostly the flexible baking dishes or muffin cups, but you should read the label information for the product you have.
Best Answer
The reason not to use scratched glass bakeware is because the internal stresses encountered during heating can (rarely) cause the bakeware to violently fracture along the scratches. That doesn't really apply to glass tableware, which doesn't encounter the same temperatures (though cracked tableware, of multiple materials, will occasionally break from thermal stress in the dishwasher).
Incidentally, glass bakeware and tableware should be made from borosilicate glass, which cannot be scratched by steel cutlery.
EDIT: Also: Don't use glass tableware for hot food. Irrespective of safety issues, the thermal density and thermal conductivity of glass means that it will quickly wick away heat from any food which is placed on it. Glass plates are fine for salads and stuff, but they don't make good general-use dinner plates.