Listen everything in an animal aside from the bodily fluids is basically elastic. Blood vessels, hide, organs tendons you name it.......if things didn't have elasticity animals in general would snap organs and vessels and everything else inside the first time they jump up and down.

Dull allows blades to push aside elastic materials.........slide one through a rubber band once and tell me how great it works. Arteries and veins are very much like a rubber band in toughness. They have to be orall mammals woulddie during everyday activities.
Dull equals less trauma, lessened bleeding and potentially uncut vessels and slower death.

No, Your exactly right, think about all of the veins and arterys running through a deers vital, a sharp blade will severe(sp) the aterys/veins where as a dull one would push, stretch, bruise them. Like a rubber band, push a sharp one accross them, then push a dull one.