Anticipation for Apple’s rumored iWatch is getting higher and higher. In fact, I’m in the market for a new watch, and the idea of a connected, multi-sensored, paradigm-smashing new device is tempting. But I’m also a little skeptical that, if this device ever ships, Apple will be able to deliver something I’ll actually want to wear.

That’s not to say that I don’t believe that an Internet of things-native wearable device will turn into a legitimate market; in fact, I do. The question is how long will it take? In my view there are some major hurdles to getting there, not the least of which is surmounting a challenge that the technology industry has never really mastered before: creating fashionable goods. That’s a very different problem from creating goods that are fashionable, which is more typically what tech companies are capable of.

The iPod was fashionable, to be sure, but its cultural cachet started from the inside out, from the very innards of the technology, which drove the form factor. Smartphones have done an arguably even better job of getting closer to the ideal of an object’s physical appearance dictating its technological composition, but at the end of the day it’s still very much the way these objects work that govern how they look.

Things that you wear are a wholly different proposition. There is almost literally no reason why we need collars on a shirt, frills on a blouse, pleats on a pair of pants (actually, there is no good reason for pleats on pants for men, at least until the winds of fashion decide the opposite), or any of the countless design details that make what we wear compelling to us as things that we want put on and walk out the door with. These things are designed from the outside in; they’re fashion first and goods second.

When technology companies look at goods that are built from the outside in, they generally see irrationality and inefficiency, a broken market just waiting to be corrected and “disrupted.” They believe that they can engineer so much value into these items that people will be swayed to buy goods built from the inside out, that the promise that drives hardware and software—“adopt this and benefit from its utility”—will convince people to upend their sartorial habits. This is how you get products like Google Glass, which assumes that consumers prize utility so much that they’re willing to look like they have no interest whatsoever in having intimate relations with another human being.

I’m kind of joking about that, but I’m kind of not joking too. The things that we wear aren’t just an expression of who we are, they are an expression of who we want to be with—as friends, as neighbors, as fans, as lovers. A shirt, a pair of glasses, a necktie, a pair of shoes…these are methods that we use to make a connection between our inner selves and other people. We use fashion to signal our particular humanity to other human beings. Fashion can be trite and superficial and, in my experience meeting members of the industry, it can be a magnet for some of the least interesting human beings on earth. Nevertheless it satisfies a deep-seated need for connectedness, and it’s an indispensable part of living in society.

Part of that indispensability, at least in consumer culture, is fashion’s endless variability, even within the dress codes that align us together into tribes. We could all choose to wear the same thing, and yet we don’t, even within groups who feel very much the same way about the same things. We need what we wear to both signal our belonging and highlight our apartness, to emphasize our individuality. And we find it intolerable when it promises to do that and fails, when someone else shows up in that same cocktail dress at that party that we’ve been waiting all season for.

This is a key economic challenge to making wearables: how do you create variability at scale? It’s very difficult to do that until your components are commoditized, until the materials that you use to make a fashionable good are so plentiful and source-able from so many vendors in so many different variants that you can afford to offer your garment, or your shoe, or your eyeglass frames in literally dozens of different styles and color ways. Until you have a commoditized supply chain—which is in many ways the anathema of Apple’s business model—the best that you can do is offer your phone in three or four basic colors.

That kind of limit to personal expressiveness will work fine for Silicon Valley, a place where it’s the height of fashion to walk around with a cleanly pressed dress shirt left untucked. But for the rest of the consumer world, it’s going to be very difficult to sell tens, much less hundreds of millions of any given wearable device in the exact same style. The first few dozen, or even few hundred, devices in this category will almost certainly all be designed to be as broadly appealing as possible, will take the least offensive approach to their form factors, and so will appeal to relatively few of us. At some point circumstances will allow this to change, and designers of wearable devices will be able to create products much closer in spirit to the garments and accessories we know today. Maybe Apple will even be able to leapfrog its way there, or accelerate the journey. But in the meantime it seems unlikely that the road to a truly robust wearables market will be a smooth one.