To be honest, i think even in historic times the vast majority of this region was always thought of as seperate from africa and asia and europe, no matter what demonym they used to describe those peoples.

I'm sorry but this just isn't right, this region was always considered Northeastern Africa throughout all of antiquity although its names and borders have always changed depending on who controlled the area during different time periods (and this has been by far the most contested region on the planet throughout history). But again - it was always considered a part of the African continent.

You're right in saying that was somewhat distinct from "mainland Africa", but it would've been called something like "Northeast Africa" as opposed to being totally distinct as its own place as it is now after being dubbed "Middle East".

You may find it interesting to hear that this continent was referred to as "Eden" in antiquity (the Hebrew word for paradise) before the Romans came along and renamed it to their equivalent of "Africa", but that's a bit outside the topic of this discussion.

If you want some good reading material on this, I would recommend a book called Is There a Middle East and perhaps an even better one called London and the Invention of the Middle East.

What if they used the term "Middle East" for a specific purpose?

Check out those two books I mentioned, particularly the second one, and you'll find that this was most definitely the case.

The europeans, most likely the British, are the originators of this term. For brevity, ill save consideration of purpose for later comment. However, i would make a small bet that says it has something to do with Greenwich and the designation of the Prime Meridian.

You are correct, although the reasons are far more numerous than just the one you mentioned.

Edit: If you asked 50 people where Egypt is, 48 of them will probably tell you "the Middle East".