I've only seen the one bullfight. I went so that I could see for myself something I'd only ever heard about. It was every bit as gory and disturbing to watch as you might think it is. I'm not going to defend the practice but I think I can explain it.
It is real. In a world of make-believe conflict where "entertainment" invents situations that look dangerous but really are not... a bullfight is a real fight to the death. No fake blood. No fake risk. The real deal.
No, it's not a fair fight, but it is an honest one. I was surprised at how great the risk was to the matador. I expected a more contrived bull-killing show where the staging of it made it basically impossible for the bull to really get to the matador. Not the case at all. No, the bull doesn't have much chance of leaving the bullring alive, but the matador has a very real chance of death as well. Not a big chance, but a real one.
Compare this to entertainment like "The Fear Factor" or other such TV shows. The "fear" is all in the mind. Any real risk is carefully engineered out with safety equipment and staging. In the bullring there is no safety cage and no harness to pull the matador out of trouble. In fact the matador doesn't merely face an angry bull-- he intentionally makes the bull even angrier and more unpredictable. The picadores are there to try to help him, but its pretty obvious that they'll be there only after he's already in pretty serious trouble.
There is a certain cruelty to it, no way to deny that. In life and in nature there is unspeakable cruelty and pain all around us that we pretend to be insulated from. The gazelle that dies in the teeth of a lion suffers just as the mouse that is killed by a cat. The bull suffers at the hands of the matador. It is a predator/prey story in cinema verite. There's no pretending. No insulation. No play-acting.
So there's my take on it. I'm glad I went, but I'm not sure I'd bother to go again. It was mezmerizing, disturbing, thrilling and revolting all at once. Sure, I cheered for the matador... because he was ~really~ good at what he did, and it did require real courage, not TV-show courage.
But once is probably enough.
I don't suppose that bullfighting will survive much longer in today's world. People today need to know that their entertainment is harmless, and frankly... I'm OK with that too.