Probably because by default they advertise the AppleCare+ included price. I think you can get it without it, though. My gripe is the hard credit check they do. It just seems silly to ding someone for an iPhone.
Having come from a family business where I watched people with ridiculous credit walk thru the door consistently, I'm also overly sensitive to this. I'm not sure I'd even want the "ding" for a loaded Mac Pro, but at least it would be worth consideration.