To clarify: I'm not talking about if pets in general can give emotional support to their owners, of course they can.
I mean should the concept of Emotional Support Animals get treated with the same level of respect and seriousness as that of regular Service Animals for the physically disabled.
Anyone can legally ask practically anything they want. There's just nothing compelling you to show them anything in 99% of circumstances.
Pretty sure you can just say, "no, sorry, you can't bring an ESA in here" though. Because they're not service animals.