You're right, it doesn't make sense, but neither do a lot of other things? Why do bandits not get attacked by the skeletons, zombies, and giant rats living beside them in caves? Why are there Nehrimese soldiers in northern ruins? Why do caves and dungeons where no human has set foot for hundreds of years have burning torches and candles? Why are so many potions in caves and dungeons rancid, yet right beside them are apples, potatoes and carrots in perfect condition? Why do spiders have 8 legs when insects do perfectly well with only 6? (sorry, got carried away there)