To be fair, I haven't seen people criticizing legitimate service dogs in this thread - the criticism has been for the fakers. And you can tell who the fakers are because there is a code of conduct both for the service dog and the owner. And worse yet are the so-called doglovers who help propagate the breaking of the code of conduct by hugging or petting the fake service dog.
And understand that I'm not labeling a dog as a fake service dog because the condition they are there for is not obvious. I know there are conditions calling for the use of a service dog like seizures, diabetes, PTSD, etc. But as someone who contributes to the training of these dogs I'd imagine you are familiar with the code of conduct for these dogs. I base my perception that a given dog is a fake service dog strictly on the dog and owner's behavior. The really sad thing is that the existence of the fakes, and their entitled owners, can cause people who are uneducated about this to look askance at legitimate service dogs just because they are there to help someone with one of those non-obvious conditions. People with fake service dogs are no better than non-handicapped people parking in a handicap parking spot.