You just. Don't. Get it.
You realize that your home and car, where you dog sits, lays down, etc. - have his fecal matter everywhere? And I am not just the stuff you can see. Not to mention hair, dander, etc. It's not about being "centered on him" - it's about the environment that is not designed to be sanitized in the way that it needs to be in order for others to not be exposed to allergens and other things associated with your dog.
The only childish thing is thinking that you need to bring your pet with you everywhere you go.
News flash, everything you touch at WDW is covered in germs, fecal matter and the like. The world as a whole you inhabit is covered in the same. I too leave traces of hair, dander, and fecal matter everywhere I go. Just imagine how much fecal matter is flying around in the parks bathrooms everything a toilet is flushed.
Animals live on Disney property and in the parks, birds, rabbits, feral cats, deer, alligators and more. If Disney can handle cleaning up all manner of human fluids like vomit, diarrhea, urine and more they can handle anything that might happen with a service dog.
Also, I don't know if you realize this or not but humans also will leave hair, dead skin, bodily fluids, blood in that bed you are sleeping in at the hotels.
I'm sorry someone may have an allergy to pet dander, but you know what... I'm allergic to pollen and certain foods but you don't see me DEMANDING Disney remove any chance of me coming in contact with those elements. Instead I understand the environment I am entering and take proper precautions and rely on certain policies and procedures Disney has in place to keep me safe and able to enjoy their parks and resorts.
I can understand someone being upset that a favorite hotel of theirs is now accommodating dogs and that may impact their vacation but just like visiting the parks, Disney is allowed to change their policies and procedures at any point.
And for the record I never said I needed to take my pet with me everywhere I go.