ED nurse here...
First, let me just say this post doesn't differ from what I experience every day at work. It seems us ED nurses are always at odds with the other floors.
I personally send patients up as soon as a bed is available UNLESS I am with a STAT patient OR if I need to get a med started before sending the patient. I don't ever wait for a certain time. And you better believe our charge nurse is breathing down our necks to make sure when that admit bed is ready, we are sending our patients up so the charge nurse can put a new patient in that room.
I also will send report up and call to give report. If nobody answers, I will call until I get somebody. Even if that means calling the charge nurse and giving them report.
Yes other floors have emergencies but I've been on the floor and worked in ED and find our ED to be full of critical patients, especially all the STAT respiratory patients this winter.
I don't truly think anyone can have empathy for floor/ED nurses until you've held that position.