Implied meaning of "drilling out screw" is to retain original threads, as this is THE ONLY way to retain screw position (without plugging the hole up and trying anew), the smaller the screw the harder to impossible this is. This is critical in places where location of a screw also means registration with other components.
But when one drills out a screw with larger bit, well ... the screw is out, the hole is now bigger and nearly guaranteed to be centered differently. For parts and locations where final look and integrity of design is important (or critical) this is a "duct tape" solution.