It's the same old "if it's not cute and fluffy and it doesn't have cute, big, sad eyes it doesn't matter if it suffers."
You can see the same thing in zoos. Tigers, bears and primates get nice big, beautiful cages.
Fish get a small tank.
Shrimp get a tank so slim that the shrimp can't even turn, so it's always perfectly visible. (As seen in the Haus des Meeres in Vienna)