I think feeder goldfish are treated 1000% better then saltwater aquaria. After all they are raised for one thing and that is to be food. We are not going into their homes and taking them away for their families and friends like we do with saltwater fish
But let me tell you a little story when I was a young private in the army. I had a Master Sergeant I worked with who was into fighting c*ocks. And I questioned him about it. And he explained it to me as such. You take to c*ocks and put them on a desert island they will kill each other. You put a c*ck in front of a mirror and the c*ck will try and kill its own reflection. And this would be done even if the c*ck has never seen another c*ck in its life. It is just natural. And then he goes on to say when you have a fighting c*ock you treat and care for it far better then if it was anywhere else. Heck the champion c*ocks are worth thousands of dollars and live the lives of kings.
As far as seeing a post about Harlequin Shrimp is dying, come on, a shrimp is not like a fish or coral where there are signs of it being in bad health.
But I think you as well are resses are just trying to justify the keeping of Harlequin Shrimp by stating examples of other unethical situations that might be worse.