It's sometimes hard to tell when someone has crossed a line from using resources to taking advantage of the system for their own agenda. Emotional support animals can be beneficial forms of therapy for people with various mental disorders, but unlike guide dogs, they have as much power in the eyes of the law as a regular pet would.
When I say that it can be difficult to tell who needs these resources and who doesn't, I mostly mean it in the context of emotional support dogs and cats. In the case of emotional support monkeys however, a line has clearly been crossed.