According to a book I read by S.I. Hayakawa called "Language in thought and action," there is a valid reason. I read it a while ago in AP english.
It's not any of the religious reasons you might think, or mind control oppressive tendencies. If you put all that aside, it is important to have a "safetey valve" in language so we can fall back on words instead of actions which have more serious consequences. Human beings are the talking animals, so we resort to words first. Seems like a sterile reason to me, but it makes sense according to Hayakawa.
Something I just thought of is it may be related to the tendency of some creatures to yelp when injuired. But that again may only apply to pack animals like dogs/wolves who do have basic vocal communication. I know when I step on my dog's tail or paw, i'm gonna hear some vulgar vocal expressions.