What's the big deal with fabrication debris?

[mistersqueegee]

Here's a video showing why we deal w/ this defect on the surface when it used to be kept inside the glass unit -
http://www.youtube.com/watch?v=4hA1gZ7xkP8&list=UUiQAbZRD89Qd0VX1NNcgq_A&index=5&feature=plcp