I can understand concerns with whaling because the whales are taken out of the ocean and killed.. As a saltwater aquarium owner I know I cherish my fish and corals. The point being having tropical fish should be the least of their worries. Its not like fishing where you mount your catch on the wall, my fish are like part of the family and I take very very good care of them and provide a suitable environment for them.
Problem is our hobby is not viewed as that.. Its more viewed as wanting to posses exotics. Look more people are interested in collecting corals than in the biology. Corals are not thought of animals. Over half corals and fish die before even making it in our tanks. Go to my local fish store and they have 8 tangs in a small tank and there stomachs are all caved in. About a 1/3 of their saltwater tanks have fish dieing in them. They throw carpet anemones in tanks with one normal fluorescent light. Look how many people on the forums buy things and cant even keep them alive or buy and then do the research instead of researching and then buying.. Forums dont help the situation either because they give access to these people looking for ammo against the hobby.