why is training with food so bad?

I'm perplexed at the amount of trainers I see polarized in their approach to dog training: either all compulsion based or all reward based. I saw a post the other day on facebook by a trainer who boasted of how he was able to get a few dogs, that had aggression issues, to sit together. It's sort of like posting, "Look how I was able to get these guys to paint my house, and I never paid them."

The fact that some trainers brag that they can get dogs to do something without rewarding them is a cheap shot. On the other hand there are those trainers that will nag a dog to death, constantly trying to force treats and toys on them in order to get them to comply.

People always comment on how my dog looks at me in adoration. He does Schutzhund and has a great bite, he's strong as can be and I can tell you that he's been trained with treats and toys. Yes, he's received a correction or two, but never in training. So many of these people who train using compulsion methods "do" get their dogs to comply, but you can see that "compliance" look on their faces (the dog's face) from across the field.

My point is simple; dogs should be treated with respect and compassion. Everything in training should start with a toy or a treat and let the dog take it from there. I even take this approach with aggression. If a dog can be distracted or deterred from aggression using a toy or treat, that is the right approach. Where I differ with other trainers is that I don't believe in two things:
1. nagging the dog to death to get his compliance when dealing with dominnace or aggression
2. giving up on a dog if the treat and toy method fails.

That being said, I rest my case on the statement, "What's so bad about using treats to train a dog?"