$150-$300 doesn't guarantee a lifetime of good behaviors. we routinely take refresher courses every two years, and we still have problems sometimes even WITH training at home (and yes, imagine that i know how to train dogs, and have done it for work before!). even if you do go to classes it's not for sure that the trainer you get will have methods that your dog will respond to. then what, go pay for another trainer? if something works there's nothing wrong with it, esp. if it means the difference between a dog AND the owner being miserable and them being able to go out together and enjoying life together.
people do a TON of research to find out what works for them. they don't go out and buy every single training tool on the market. face it, people do do their research and they get what works and what their dog responds to. professional training isn't for every dog or every person / family. what do you think people are doing when they get the halti leads, etc? playing a game? no, they're training their dog with a method that works. you're right, nothing is worst than a poorly trained giant dog, or one that needs alternative methods used with them. except one that's not under control b/c you don't believe in training tools.
oh, large dog owners typically do have better behaved dogs, because they understand the need to control their dogs with whatever method that works. BUT small dogs can do a lot of damage too. didn't you hear about the baby who's toes were chewed off by the PUPPY that weighed about 10lbs? or what about all the children who's faces are ripped off by toy breeds b/c the people thought they were "harmless."