In my opinion it isn't sad that they don't take bitcoin, nor would it be cool if they did. I come from a country where cockfighting is illegal and is probably considered animal abuse (which it is) by the majority of people. I'm not against killing animals for food, since they're killed quickly and without suffering AFAIK. When you force two animals to fight to the death even if they're chickens, that's not cool.
It's not the part where two chickens are fighting to the death is cool, rather the part where cryptocurrencies will reach to them and maybe use it for that. I'm not into cockfighting nor will I support this kind of thing but it's just surprising that there's someone live streaming it and let people bet on it, why not just use bitcoin instead?
I think your "AFAIK" should have a different view. Check this article by PETA
https://www.peta.org/issues/animals-used-for-food/factory-farming/chickens/