*shrug*
Every culture has it's do and don't eat animals. I eat cows. I love to eat cows. I eat pigs. I especially love to eat pigs. I don't eat dogs. I wouldn't eat a dog unless I was truly starving to death, and even then, I wouldn't eat MY dog. Also, not going to eat a horse. Personally, I think horses are for riding, not eating.
I also would not tolerate another culture coming here and telling me that I can't eat the "sacred" cows or the "filthy" pigs. Which leads me to think it's highly hypocritical of me to go over to Korea and say "You can't eat these dogs and horses that you legally aquired from wherever".
I think it's kind of shitty that a horse trained at that level ended up in a South Korean meat market, but presumably it got there legally and if the former owners don't like it, maybe they shouldn't have sold it in the first place.