This issue is like so many others. Inconsiderate and childish people abusing a privilege for which others do have a real need. Emotional support dogs are no joke, for people with severe anxiety and panic disorders, ptsd, people with autism/aspergers, even very severe adhd, who are prone to overstimulation induced breakdowns (if you've never experienced or loved someone who's experienced this first hand, don't dismiss or judge) - animals can indeed prove comforting in a way that humans can't always be, especially for people whose condition makes social interaction inherently unpleasant/hard to figure out. I'm all for emotional support dogs. Provided they are from reputable trainers and are not in any way going to be a problem (aggression, chewing things up, body functions, excessive shedding, barking) and provided the persons need is medically acknowledged.
That being said, it seems that many folks basically concoct some reason to be exempt from the rules and expectations we all abide by. There's always people scamming the system, thinking the rules don't apply to them and getting around responsibility, or abusing privileges that are supposed to be reserved for people with actual problems. It's the same with welfare, unemployment insurance, disability...I'm so thankful we have these things to protect those who actually need them. I'm so disgusted by people who plainly aren't trying and expect to be catered to. I'm glad public places, even eating establishments, are becoming more understanding and tolerant of service animals. I'm disgusted by people who have plainly invented a problem so they can do whatever they want and not be told they can't, or get out of having to do what everyone else has to do.
Heck even guns and hunting are a huge example of this problem. A few stupid, immoral, inconsiderate, unethical, irresponsible, "the rules don't apply to me - it's not really trespassing" type of people make it so that society increasing says no one should have guns and landowners increasingly say "no one can hunt on my property".