Streamlining. New target audience doesn't have the patience/attention span to seek out weapons that are specially used to kill undead.
I bet they would if it wasn't limited to 1 ridiculously rare creature. I've killed over 500 animals alone in Skyrim, and if you sum up everything I've killed, it's more than 1500 "things." I've only battled 2 ghosts, as far as I can remember. They were some guys in a dungeon shouting "I"m sorry, I have no choice!"
Soooo, I think it would just be an annoyance.
And in my case it wouldn't matter anyway, since I'm using destruction/one handed equally.