Its not hard to pick up the phone and say "911". What is hard is instructing a screaming mother how to perform CPR on her infant, what is hard is instructing the panicked kid whos dad is beating mom into a pulp, what is hard is listening to people die on the phone, what is hard is listening to officers scream for help after they were shot.
I'm not citing cliches; I'm citing experiences I personally have had answering calls. I left after 9 years, but retirement for this field is 30 years service (10 more than officers/firefighters), and the average career length of an emergency dispatcher is less than 3 years due to stress. I'm not looking for sympathy, I chose the field, but understand this isn't data-entry and not everyone can do it.

On top of the stress factors, there is substantial training involved. Medical dispatchers carry liability so they have to be certified and maintain proficiency on medical protocols, mind you, they can never touch a patient.