Here's my two cents for what they are worth. Mind you I am a 4th yr med student so my ED experience is limited compared to many. Anyhow, as far as the anything that is done in EM doesn't require 3 yrs of training...I would assume that they are speaking about the skills aspect. We intubate, suture, splint, cast, chest tubes, etc...there are more, but you get the jist. The long and short is ANY skill can be taught and does not require years of training. That part is true. So does that mean that the skills of the surgeons do not require 5 years of training. I mean that's all that they do is skill and technique. ABSO-FREAKIN-LUTELY-NOT!!! They better know what they are looking at, what the indications are for their procedures and expected complications. It's not about the the procedures and skills, it's about knowing when to use them, knowing which is better over another and what to expect if it goes wrong.
Personally, EM isn't about knowing everything, having the best equipment or whatever beefs these people are willing to bring up. It's about wanting to be that person that meets desperation at the door, that has some sick part about them that enjoys chaos, and has confidence in their quick decisions that don't always have the luxury of all the information. The ED is not for everyone.
I know many internists who bag on the ED everyday for the "crap admissions" but when they have to spend a month on their EM rotation, they freak out because they can't handle that many patients with acute problems and people pulling you every which way. Internists certainly have the knowledge to do emergency medicine, just not the personality or drive.
My gut feeling is that you were discussing this with a surgeon or a student who wants to be a surgeon. That seems to be where the most animosity (in my limited experience) is generated. I don't know where you are in your training, but you will quickly realize that every discipline of medicine is like a high school clique. Surgeons hate...well everyone because none of us know what we are doing. Internists hate FP because they never work up a patient appropriately or know how to do appropriate follow up. Ob/Gyn dislike FP because...well Ob dislikes everyone (they are not happy people). You catch my drift.
This undoubtedly is of no help, but I just felt like responding to you because I have had these same conversations trying to defend my career choice. Hang in there, they will envy you one day when you don't have to round, take call, round, or get pages in the middle of your off day, holiday or sleep.