You seem to be treating a 'culture' as if it were an individual with rights. I'm sorry, but no. I do not respect all aspects of all cultures. Cultures change over time, as they should. If they stagnate, they are generally doomed. It's time for Spain to join the first world in prohibiting blood sports. Their culture needs to change.
Just because it's old doesn't make it valuable.
'Tradition' has been used as an excuse for continuing a wide variety of evil and reprehensible things. It is not a valid excuse. Obviously, all Spanish people do not agree with bullfighting. The Spanish are the ones who will vote to keep or abolish this practice. All we can do is give them our opinion, and they will then choose to listen to it, or not.
I am certainly not going to keep my mouth shut for fear of contaminating their 'culture'.
At what point did culture become more important than life or death, or suffering?
Maybe we should start feeding people to lions and crocodiles again. That was a grand tradition in Rome, after all.