So you can die of scalp being ripped off ?

If you loose to much blood, you die. You loose alot of blood through the wound, when you're scalped. Island is not a country with Hospitals every 15 minutes of road. So: you loose blood, you loose lots of blood, and then you die, all before reaching the doctor or the hospital.

As the other poster said the first factor would be blood loss, the second shock.
That much pain could easily kill you by itself, go into shock, pass out, never wake up.

Same principle as folk who take huge falls, shock has killed most well before they hit the ground.

"Be the change you wish to see in the world"