Say I was able to scan the original photo in as greyscale, and save it as high res jpeg, could i then just drop it into my illustrator file and that be it?
Presuming it IS a photo, and not a halftone print of one, then yes.
Your annoyance should certainly not be with Adobe. They aren't responsible for the fact that the image you've been supplied with has a halftone pattern on it. They do however supply probably the best tool for eliminating it.