Yeah, they should, and occassionally one of those bulls sinks his horns in a body. Not too often, unfortately.
But yes, it's a very cruel and inhumane activity. The people who watch it are not much better than the person who is torturing the bull.
BTW did you know that those bulls are fed only salt a few days before their 'show'? This makes them agressive, else they wouldn't even attack at first and once they would attack they would crush that puny Human which is torturing them in a few seconds.