Bull riding is probably the most dangerous sport in the world in terms of head injuries.
Putting gloves on the fighters was a symbolic change that suggested that we were now making it a civilized sport, and it was no longer this crazy gladiatorial throwback to ancient Rome. It's even in our language: If you want to get serious and violent, what do you do? You "take the gloves off." Bare-fisted is supposedly a much more dangerous way to hit someone. But we've got it completely backward. The glove is a weapon. It massively accentuates the ability of the fist to do harm.
My reason for arguing against abolishing these types of sports isn't some kind of lofty, philosophical rationale. It's just that I did it and I liked it. It comes down to a libertarian issue for me. I feel that if I know the risks and I want to take them, I should be allowed to do so.
I think what bothers us about fighting sports isn't the damage to the athlete but the fact that you win by doing more harm to your opponent than he does to you. It just seems ugly.
I think the proper attitude toward fighting sports is one of ambivalence. You can be drawn to them, but you should also be repelled by them.
In an effort to civilize combat sports, authorities mandated padded gloves and instantly made the sports far more savage. Granted, putting gloves on the hands seems like a nice thing to do. If you were being punched in the brain by a powerful man, wouldn't you rather he strap a pillow around his fist? But the glove doesn't do anything to diminish your brain damage.
I don't think people are reacting primarily to the danger of the sport. There are many other activities that are truly dangerous that we have no inclination to ban.