But you can play music on a smartwatch!
Apple is all about iTunes and playing music so at first blush it would seem to be a perfect fit with the smartwatch. But when you think it through, that's not a practical function for a watch. The watch could wirelessly connect to another device to access the music library, a smartphone makes the most sense, which means either Bluetooth or wi-fi. Wi-fi would be the most practical since the watch would also need it to connect to the web for other stuff.
Having to tether the iWatch to another device makes no sense. Music can already be played on those other devices so why turn listening to music into a two device process?
A better method would be to have music functions totally contained within the watch. That would probably be Apple's preferred method. Having a big music collection reside on the watch isn't practical for the large storage capacity that would need. So you'd need to be streaming music from the cloud like on iOS and OS X, which raises a connectivity issue that would likely turn buyers off.
Wi-fi could be used but then you could only listen to music when a hotspot is available. To be practical the smartwatch would need some sort of 3G or 4G connectivity, which would be a show stopper. Nobody, and I mean nobody, wants a watch that requires interaction with a carrier. We hate our carriers already and don't need yet another device to remind us why that is.
Of course you could tether to a phone, but that turns enjoying music into a two device process again. That's just not practical for running around town every day.
On the smartphone the earbuds can stay in the bag and the phone still be used without them. That wouldn't be the case with a watch phone.
Connectivity issues aside, another problem with using a smartwatch to listen to music is how to hear it in public. On the smartphone almost everyone uses wired earbuds and that would be the case with the watch. The problem is it's not practical to plug earbuds into a watch as the wire would get in the way. It would have to be much longer than earbuds used with a phone as it would have to handle any position of the arm wearing the watch. If the wire is too short, those earbuds would be yanked rudely out of the ears if the arm was stretched out. Plus it's not very practical to have the watch tethered to the ears in many situations.
Wireless headphones could be used instead, but few people are willing to use them with phones and the watch will be no different. Even if Apple could convince the masses to use wireless headphones with its magical smartwatch, the reality of having to keep them charged would quickly turn the crowd against it.
Speaking of charging, that brings up another issue that buyers won't like, and that's having a watch (no matter how magical) that has to be charged regularly. People are not going to be happy when their shiny new smartwatch goes dark during the day because they forgot to charge it. This will drive home that the watch doesn't add enough fun and functionality to be worth the hassle of making sure it's charged, updated, and keeping up with the latest cool apps.
But it's a phone!
One function that Apple could put on the iWatch that's not been done in a practical way is to put a whole phone inside it. This Dick Tracy watch would have to handle all phone functions to be worth the effort of using it, and that raises even more issues.
Talking directly to the watch on phone calls would not work in public as it would be like using a phone on speakerphone all the time. The only way to avoid that is to use some kind of headset. That means wires or some kind of wireless headset as used for listening to music which is as impractical for calls as it is for listening to music.
Some buyers might be willing to use wired earbuds like they do with their iPhone but they'd get tired of always having to do so. On the smartphone the earbuds can stay in the bag and the phone still be used without them. That wouldn't be the case with a watch phone, a big disadvantage compared to a standard phone. And I don't think many users would be willing to go back to those dorky Bluetooth headsets.
Don't count Apple out yet
Apple has surprised us before and while I don't think it can solve these problems perhaps it has one more thing. Maybe they've figured out how to address all the issues I've raised, and come up with a unique, compelling function to get us to snap up the iWatch.
If they do release a watch that doesn't address the problems outlined here I predict the iWatch will fail miserably. Of course, I've been wrong before so Apple might just make me eat crow.
I'm not a smartwatch designer nor do I play one on the internet so take this with a grain of salt. Actually, I guess I am sort of playing one right now. On the internet.