Ethics is in the eyes of the beholder. It all depends on where you stand in the spectrums of things.
If you were a fish - do you like your killer more because you become his meal with a hook in the mouth than from the side?
Do you deserve to die more because you just want to eat a meal?
If you were a eagle, a bear, or all sorts of life forms which have to depend on the annual return of salmon for substaining them to live through winter (and therefore the survival of their species) - what? you crazy humans, you mean we have to bite, claw or beak the salmon in the mouth before we can deserve the fish
If you are among the starving people in the 3rd world - this debate is for you idiots of the rich and spoiled people of the industrialized world? Want to change place for a day?
If you are buddist or a PETA member - do you think it is ethical killing a fish, even for a meal? You murderers and killers..... murder, murder murder, kill, kill, kill.
If you are a flyfishing purist - the debate on your crude and unsophisticated way of fishing is a joke? Want to try weightless flossing which is lead free?
If you are a catch & release purist - we are more ethical because we are going to put the fish through hell, then kiss it good bye & say 'thank you buddy' for a great fight to make my day a happy day'. What? It is unethical to build your fun on others' suffering? Na! Get lost!
If you are a bar-fisher, do you think it is ethical to fish with a ton of lead, polluting the river and its near shore ecology (forget about where the hook is located), as it is much more unethical and much worst to the fish and its habitat to flood the river with unretrievable lead bombs so that you can eat your fish.
Alwaysfishin is right. Fishing was originally a way of collecting meat to feed the family in the ancient days, much like hunting for games. As long as you are fishing for food, using the most efficient and legal method is good and ethical. People of old used the most efficient methods which won't harm fish stock much, because they were not killing fish massively which made fishing sustainable in the past. Even when nets were used, they were small cast nets or dip nets, or spears, never the mighty fish killing machine like the drift/gill nets and seine nets of today.
So, I am happy to fish a legal and ethical method which is the most efficient method for a fisherman with one rod and one hook on the Fraser. In the smaller systems, it is a different story, as other methods are more efficient and it is foul hooking too many fish in the body other than the mouth. It should be banned or discouraged.