Should airlines accommodate emotional support animals?

“An emotional support animal is a type of animal that provides comfort to help relieve a symptom or effect of a person's disability such as anxiety. Under U.S. law, an emotional support animal is not a pet and is generally not restricted by species. An emotional support animal differs from a service animal”. —Wikipedia

So generally, emotional support animals were legally allowed to accompany passengers on flights, but some airlines are now forgoing that under a private business loophole and the fact they are accredited as service animals. What are your thoughts?