Existing MP3 players offered a pretty rough user experience; the iPod was a pleasure to use in comparison. Largely the same was true of iPhone as compared to existing smartphones. The first generations of iPod and iPhone also had hardware that was strikingly attractive and even more important, ready for prime time: well able to meet the needs of their software and of the use cases they were designed for. The Apple Watch has lovely fit and finish but looks portly and awkward, and faces serious questions on the basic criterion of battery life. The UI looks promising, but from what there is to see so far it doesn't look as if it's going to blow Android Wear out of the water. (The "digital crown" looks promising, though!)
Moreover, even without a second 5GB of storage or wireless, the iPod had a compelling "value proposition" that was soon clear to everyone, even if it wasn't immediately clear to CmdrTaco: "portable MP3 player that doesn't suck". What's the comparable pitch for the first-gen Apple Watch; what does it offer that feels like a must-have, rather than a nice-to-have, and which you can't do fairly well using your smartphone?
None of this is to say that the Watch is terrible, or will fail, or will never amount to anything. But the CmdrTaco analogy seems clearly inaccurate to me at this stage.