You have obviously never hunted wild birds before or are a much better shot than 90% of the people in the world. The LAST thing you want your dog to do is drop a live bird "within a step or 2" because the bird will be gone before you can make that "step or 2".
A trained retrieve should be done to any and all hunting dogs. Its not just for the trialers or testers but ensures dead and wounded game will have a higher chance of making it into the bag than a dog that hasnt had a trained retrieve. Not to mention if done right the dog will not give up on a search until the master tells the dog so.
my dogs never give up, they quit only if told to do so. My comment was geared toward lower prey drive dogs. If I have to command a dog to keep searching that dog is not the dog for me. If my dogs are sent to hunt dead they are given 1 command -search, if they are sent to retrieve and for some reason have difficulty completeing it (bird has left ,cover is thick,poor marking,ect) then they will search until told otherwise. My home only has room for very high prey drive dogs.
I don't agree 100% with your first paragraph but that's ok, we each have our own opinions and experiences.