It would have been somewhat more acceptable if it had been organized by ferocious animals instead of cockfighting. But the animals by which they are organized are called domestic animals. As a result, if you gamble by harming those animals, there should be more pain than pleasure. Although those who have already involved themselves in such activities may have rejected the affection and love they have for the animals. Moreover, Animal Resources Department will never condone such activities.
I don't think its more acceptable if the animals that are fighting with one another because humans made them do so were the cruel ones. This is because despite being violent in nature, they are still living things that deserve to live peacefully in their natural habitat. Being subjected to fighting forcefully just for the sake of entertainment and betting isn't justifiable. It's unhumane. These kinds of cruelty should be stopped because animals aren't toys to be played with.
Human aren't the only ones who feel pain and suffering. Animals can feel those too. For sure if you were on the shoes of those game cocks and other animals that are required to fight for survival, you wouldn't feel amused.