Scaling works well when origin centered flag is on (ie. there is no translation to keep the mesh centered while scaling). When trying to keep the mesh centered though, the method is well behaved when the origin of the mesh is at the edge. The scaling looks off when the origin is at the center of the mesh already because now no translation is needed. The same applies whenever the origin is not at the edge. A good example to look at is platter's monkey.obj.
Scaling works well when origin centered flag is on (ie. there is no translation to keep the mesh centered while scaling). When trying to keep the mesh centered though, the method is well behaved when the origin of the mesh is at the edge. The scaling looks off when the origin is at the center of the mesh already because now no translation is needed. The same applies whenever the origin is not at the edge. A good example to look at is platter's monkey.obj.