If the dog is a certified service animal, then that individual could then be asked for paperwork because it needs more training and caused a health issue. If it is not a service animal, then you are judging all disabled individuals and their properly trained dogs off of one that is abusing the system. That is no different than my wife or friend taking my handicapped parking pass, using it without mea, and doing cartwheels into the store. Would you judge all people that have handicapped parking passes because someone abused the privilege or a disabled individual double parked?
As bad as it bothers you to see a dog pissing in the store, it makes actual disabled individuals even more angry. It especially angers those with service animals that have thousands of dollars in training before they even are matched with that disabled person.
Every time a person abuses the system meant to help make our lives a little more functionable, it makes the judgement of the ignorant towards us 10 times harder to deal with. Just like the woman that left her gun in the bathroom at the aquarium, does that mean all those with conceal weapons permits need more laws? Tougher regulations are called for in certain circumstances but there is no need to lump all service animals or their owners into the same judgement as the peeing dog you saw. Dogs that are aggressive or not properly potty trained, will lose their certification.