It's sad ... I didn't like it. Don't like watching humans force animals to fight. If it happens in nature, it's fine...circle of life....but don't like it being forced.
Being Spaniards, we used to go to the bullsfights religiously as well.
Look at it this way: in both arenas, the animals live their lives the best an animal can, and the animals not only have a chance to live afterwards, but to live the rest of their lives as studs, being well taken care of, even be remembered long after they are gone. You ask any bullfight aficionado who Islero was, and they'll tell who he was.
On the other hand, that fried chicken or that steak you eat, neither that chicken and that cow ever had a chance, and lived and died miserably.
That said, I have not been to either the palenque or a bullfight in 40 or so years.