The patients you don't have
Generally EMS does not transport dead bodies. It's a good way to take an ambulance out of service until the corner can get there.
While this is most certainly accurate from the EMS standpoint, for perspective, consider the veiw of the entire healthcare system.
In addition to your ambulance, you can tie up an EM physician, A critical care surgeon, a couple of nurses or techs in the ED, a bed, and not only decrease the resources for the next emergent (as we would like to define it) patient but you bring many of the other patients already in the system to a halt. (possibly for hours)
THe EM working a fruitless code is not seeing other patients, emptying ED beds and creating a patient back up.
The Critical care surgeon is not in the ICU or surgery, depriving others of the knowledge and ability.
The grunt work of the ED is not being done by the nurses which holds up the system as much as missing a physician. More if like in most trauma centers I have seen 2 nurses respond to a life threatening trauma alert. (one to document, one to work bedside) Additionally a tech (aka paramedic) in the ED can also be tied up with the body.
What happens to the body takes resources, somebody has to tag it and bag it. Inventory belongings, deal with the distraught family. (sometimes even make the body available for viewing)
A bed/room is tied up until somebody from the morgue can come and pick up the body, which is not always instantaneous, especially in larger facilities or in hospitals that don't have an in house morgue staffed 24/7. You can't simply put the body in the hall.
Whether we all like it or not, admit it or not, or wish it was different, EMS has a direct effect on every patient in a given system. Including the ones they don't bring in on their individul truck. There is usually more than one EMS agency that uses the same hospital.
In some major hospitals in the US I am familiar with EMS contributes to between 10-15% of all patients admitted on a given day. That is not the total brought in. Most EDs are self reliant, you simply cannot float people into the department and expect them to function. I have seen it in major disasters and I can tell you the floaters often cause more troubles than they help. They don't have local access to meds, they don't know where equipment is, where/how to replace it, what protocols, treatments and procedures are available and when, or even how to find patients. They are not adept at triage, or handling multiple patients of varying levels of illness injury.
I admit I am the first to call BS on the propaganda of nursing, but I also realize what the actual abilities and contributions are. There is simply no substitute for an ED or ICU nurse in their respective environments. In any hospital and most healthcare facilities, if you overwhelm nursing, the whole place comes to a grinding halt. Taking one, much less 2 out of circulation in an ED for a corpse, is just unacceptable.