Leathercraft Techniques

Ok, a question here. Sometimes, for example when they attach gussets, people pre-prick holes in both pieces and match up the holes and stitch. This is of course one instance when you may need reverse pricking irons.

Or do you? Today I stitched together two pieces that were pricked individually with regular irons, just for fun. Perfectly angled stitches and identical look on front and back - without a cast. Why isn't this something that people do? I think I have heard of one guy saying he did it and that was years ago. Is there some great drawback?