Yes, but you have to understand the iPhone's place in the market relative to the watch. The iPhone was a brand new untried product competing for a foothold in the massive cell phone market, and it was radical and untried technology compared to the reigning technology -- the Blackberry. Since then, Apple has earned a name for itself with the general public and slowly eroded the traditional phone market with its superior technology which the competition has copied and sold for less.
But the watch is totally different. There were already smart watches on the market, some as nice as Apple's. Apple has raised the bar on style, and drawn more attention to the product category as a whole, but not necessarily introduced any new radical technology that puts it in a different category than the competition like the iPhone did. The main thing it did was bring superior interface to the iPhone, that none of the existing smartwatches could compete with. So anyone who ever looked at a smartwatch and passed, already ruled out what it could do for them. But the Watch works exclusively with the iPhone, and opens up the door for a second look. Now, there's about 400 million active iPhone's worldwide. Which means in about a year, Apple has sold an Watch to less than ~4% of the clearly defined captive target market. So, while 12 to 15 million sales for any other company would be an excellent start, for Apple, it seriously underrepresents the potential market.
And here's the rub -- anyone who ever thought about a smart watch who owns an iPhone, presumably has a had a year to look at the Watch, and decided to opt in, or out. So now, Apple has to attract customers who never thought about looking at a smart watch, and again from a very specific, well defined, and active audience -- existing iPhone users. Considering Apple's reputation, and massive marketing rollout for the watch, I'd say that anyone who was seriously considering an Watch has had a year to decide whether they were interested or not. And you've got a massive ~96% of all iPhone users who voted no. So for Apple that's a pretty big loss. Now, yes it takes time to build up interest in a new device, but for one that has a pretty well defined and targeted market, those are pretty underwhelming numbers.
That's what makes next week's event particularly disappointing if they don't introduce a new watch. Again, this is just my observation, but I'd say anybody interested in buying a Gen 1 Watch has already decided they will or won't and most of the 1st gen purchases have likely been made. Yes there will be more, but I"m hard pressed to imagine that there will even be similar numbers to the launch year over another 12 months. But a 2nd get watch with new features, or styling would get those who passed the first time to take another look. Again, compared to the iPhone, even it released a substantial upgrade every year (even if only a processor upgrade and enhanced software features), which continued to bring more attention to the platform. Call me a pessimist, but if all Apple offers are new watch bands, as rumored, I don't really see that changing anybody's mind who already passed on the watch.