The classical description of disruption in business, and especially technology, is that a new product (method, business model etc) appears that’s not as good as the existing way of doing things, but that’s much cheaper. The existing industry thinks it’s a joke, and certainly not a threat. But over time, it gets better while staying cheaper, and then, sooner or later, it’s not a joke at all.
You can see this basic story over and over again in the history of the technology industry. The future always comes looking like a toy. But right now the tech industry is being reset by the mobile, and in mobile, disruption tends to work the other way around. The new thing tends to arrive looking like an expensive luxury for rich people, doing far more than any normal person would need. But over time it gets cheaper, and the new, unnecessary characteristics turn out to be very necessary, and the the old, cheaper, less capable model gets squashed.
That is, in tech the cheap weak product generally gets better quicker than the good expensive product gets cheaper. But in mobile, the good expensive product has generally got cheaper faster than the cheap, weak product got good. Moore’s Law is operating in both cases, but the effects are different.
As for all theories, there are exceptions and gaps (‘all theories are wrong but many are useful’), but it’s worth looking at those cases where it does hold true.
The really obvious example is mobile itself. Twenty years ago cellular was an expensive luxury for millionaires and drug dealers - status symbols no normal, sensible person would ever need. You have a telephone already - who needed mobile? But once the devices and networks reached a minimum threshold the appeal of mobility was much greater than the appeal of a landline's price. (Moreover, price turned out to be more nuanced - a prepay phone can look cheaper or more expensive than a landline depending on your point of view.)
At the same time, there was a lot of debate about quite what kind of mobile network was best. Anticipating the ‘wifi is good enough’ argument of the early 2000s, there were several attempts to offer cheaper ‘limited mobility’ services that would only work if you were in a specific place. You can see an (appallingly bad) ad below for one of these in the UK, Rabbit: the PHS networks in Japan were the only, Galapogean survivor of this. It turned out that mobile phones need to be, well, mobile. (An old colleague of mine suggested that the root of all the problems in the USA was calling them ‘cell phones’ instead of the British ‘mobile phones’, but then the Germans call them ‘handys’ so who knows.)
Now, did you notice that little message at the beginning saying 'outgoing calls only'? I'd forgotten that part.
The contemporary counter to this, of course, is Iridium, which was too expensive and ‘too good’, with global coverage out of the box overshooting customer needs relative to cellular. However, though Iridium could give you a signal in the middle of the ocean or desert, it couldn’t give you a signal inside a car or an office, needing line of sight to a satellite, and the phones needed their own porter, so I’d suggest that actually, Iridium was more expensive and worse than cellular, not better.
Exactly the same thing then happened with the idea that wifi would threaten cellular - 3G got cheap enough and fast enough that ‘free’ wifi data for your phone was irrelevant, while wifi coverage never matched even the ‘good enough’ target of ‘most of a city’. Better and more expensive beat cheaper and good enough.
Arguably, you can see the same thing happening again with projects like Firefox OS. Entry-level Android phones are now well under $50 - the price window between ‘only a feature phone’ and ‘I can’t afford Android but want more’ is moving down fast. It’s tough to compete with the scale effects of the whole Shenzhen ecosystem. Again, the better, expensive product gets cheaper.
Most recently, of course, the iPhone came in at a very, very high price in the context of the phone market in 2007 (even after Apple realized it needed subsidies after all). It’s certainly valid to say that it disrupted PCs from below, but it did, actually, disrupt mobile phones as well - just ask Nokia, what’s left of it. The new paradigm was a large phone with a multi-touch screen, ‘PC-class’ OS, relative indifference to bandwidth efficiency, target battery life of a day instead of a week, and durability targeted as ‘well, don’t drop it then’. It was also an MVP (no 3G, basic camera, etc, etc). For all these reasons and more the industry laughed at it, but Apple created demand for a $600 phone on a scale that had never existed before and its cousin Android then drove the same model down to much lower prices. The Symbian model, and the feature phone model, didn’t grow to meet the new, expensive challenge - the expensive challenger model took the top of the market at a new, higher price point, and then (incarnated as Android) got cheaper and took the rest.
The fact that multitouch smartphones make different trade offs to feature phones around durability and battery life does of course blur the question of whether it is 'better' or just different. But I'd suggest 'better' is subjective: what is not in doubt is that the more expensive approach has beaten the cheaper one.
There are a bunch of different subsets to this story, of course. Another counter-example, stronger than Iridium, is that within the mobile operator industry each country generally has some operators with strong networks (good coverage, high speeds and capacity) and others with weaker networks - the stronger networks generally charge a premium, and some consumers choose to pay the extra and some decide the cheaper one is good enough. Most recently, this is what Iliad/Free is doing in France (helped by heavy regulatory support) and Deutsche Telekom's subsidiary T-Mobile is trying in the USA. But I’m not sure that counts as ‘disruption’ so much as ‘cheaper competition’, which is where I’d put Android as well: a similar product at a lower price, not a different product serving the same needs at a different price.
I don’t propose a perfect, unified theory to explain why mobile seems so often to work like this, but that's less important than the observation, I think (or, perhaps, I’m just suspicious of unified theories). The tech industry is very used to the idea that incumbents always laugh at disruption because though it’s cheap, it’s also crap, not realizing that history tells us it will get better. But we also have to remember not to laugh at things that are amazing but way too expensive, because history tells us they might get better and cheaper, faster than you can add 'amazing' and put it through a waterfall.