Legally there are a few types of animals. A real service dog is like a seeing eye dog, or a seizure warning dog. They're ridiculously trained and only available from a prescription...which is fairly difficult to get, and bringing them with you is backed up by the force of law. I'm sure the people who need service dogs really would prefer they didn't need them.
On the other hand, "emotional support animals" and "therapy animals" require little more than self-report, or an advisory note, and most of the time aren't afforded the same legal protections as genuine service dogs.
It's often up to individual establishment's policy on such animals, but few make such a differentiation since the penalty for questioning someone and getting it wrong is somewhere between a bad Yelp review and a lawsuit. It's also too easy to just put a dog in a purse and get away with it, without even the pretext of a condition. So, yeah.
Misplaced anger, man.