I have a somewhat different view on the matter. It doesn't matter whether you are home bound or limited in your life from blindness, paralysis, panic attacks, or a medical problem, you are still considered disabled. The arguments over what disabilities are more deserving or worse seems somewhat petty to me. Service dogs are for those who need them.
Which brings me to my next point. Psychiatric service dogs and owner trained service dogs are not the ones who are creating access issues for the general service dog population, it is people who are not disabled and still feel the need to take their dogs places that they are not allowed.
When I am out with Sterling, people will often ask where I got his vest, so that they can get one for their dog. Or they will tell me that they have one for their own dog so that they can take them everywhere, even though they will admit they are not disabled. These are the dogs that have no public access work, these are the ones that give the true service dogs a bad name.
I hope that people will see the harm that they are doing by impersonating service dogs, and that people will also see that impersonators are the problem, not those with different types of disabilities.