It seems like you think that treat training is the "cure all" magic training trick. Do you think that there are dogs who are too dangerous and too much of a liability to be rehabbed? I'm just asking this question out of curiosity.
No one is saying that "treat training" is a magic cure all...
Pretty much ditto TB.+R based methods (and like the others I do not limit myself to food rewards though I do use them frequently as food is a primary reinforcer AND food rewards allow for many quick repetitions) require time, consistency, and work. Hardly a magic fix.
I have yet to work with a dog who did not respond well to +R based methods (after all the laws of learning are universal! Breed and even species doesn't matter! If a dog has a functioning brain with the ability to learn learning theory applies) That would include my own dogs past (pug and boxer/mastiff type mix) and present (doberman, min pin, 2 pekingese, terrier/poodle type mix), clients (pretty wide variety of dogs including some "tough" breeds like dogos, gsd's, a mal, etc.), and dogs at the shelter (again a wide variety of breeds and mixes). If I take a step back to assess when I do have difficulty, the problem is typically a handler/training error on my part.
All of that said, sure there are dogs out there who are too dangerous or too much of a liability to be rehabbed. Personally I think most dogs can be helped but not all should or can be regardless of the method used...
Are you familiar with Ian Dunbar's bite scale?
I tend to agree with it.
And last but not least, just some food for thought on the use of aversive methods for aggression cases.
Nicole Wilde's take (she is a certified pet dog trainer and certified behavior consultant. She has a lot of experience with wolves/wolf dogs and shelter dogs)
Do Some Dogs Need a Heavier Hand? | Wilde About Dogs
And a survey/study with stats basically showing that aversive training methods carry a higher risk for an aggressive response from a dog than positive reinforcement based methods.