You simply cannot overgeneralise like that. For example, dog shows, if they can be considered a kind of sport, aren't dangerous to the dog in the slightest. The only hazard I can think of is if the owner is an abusive douchebag.
Bullfighting, on the other hand, is needlessly violent and cruel to the bull, giving it a slow death as it tries again and again to ram the matador, who's essentially mocking it the whole time.
So while some should be banned, many are alright. Nothing is that black & white.
People eating meat? You say it's wrong for animals to die gruesome deaths in (bullfights) however, cows that are killed for beef die by a comparably painful execution method; electrocution.
Why is one despised by a majority of society and killing animals for food isin't? Bull meat from bullfights is used for food for many people as well.