interesting, barnbum.
i always cut selvage to selvage also.
i learned that material is stretchier selvage to selvage than lengthwise. therefore we should cut borders parallel to the selvage, and straight (non bias) binding should be cut selvage to selvage. i don't always follow those rules but the stretchy part is true.
i hadn't heard that we should make all cuts along the selvage. what was her reasoning?