Oh really? Fair enough then. I would think if Apple did do that though, they'd want it to emit a pleasing sound, not something too harsh. Not sure how much flexibility there is with vibrating semiconductor diodes.
I'm mostly on your side, as I think a phone's speakers are best used for ringtones and notification tones and nothing else, but I think you're overstating it a little bit. The HTC One speakers are pretty well reviewed, and managed to have noticeable stereo:
EDIT: Posted before I saw the most recent reply.
I've been searching and can't find either confirmation or denial, and barely a mention of the question. I can see Mac <--> Mac as being something of a niche, but I'd have thought iPhone <--> iPad would have a wider appeal.
Any idea where you heard Mac <-> Mac? I've only heard Mac <-> iPhone/iPad. Handoff is even advertised as a Mac to iOS feature in Yosemite: http://www.apple.com/osx/preview/ and http://www.apple.com/osx/preview/mac-and-ios/ (doesn't preclude Mac to Mac, or iOS to iOS, but definitely doesn't suggest it either)