I think the creasing is a counter for the effects of rounding. So you can set an indedpendent crease in a mesh to prevent a sharp corner from being a rounded one. Improving the programs' usefulness for handling mechanical meshes.

thou and I, my friend, can, in the most flunkey world, make, each of us, one non-flunkey, one hero, if we like: that will be two heroes to begin with. (Carlyle)