One of the classical debates in computer science is convention versus configuration. This debate manifests in programming-language design, product design, marketing, what hardware and software can and cannot do, and how they do it.
In the early eras of computing, configuration reigned supreme. The first computers had no security, no encryption, no rules, and very little if any software infrastructure to sit on top of. The early computers were in many ways a clean slate, akin to John Locke's tabula rasa. Not only did the software epitomize configuration, so did the hardware. Before the Apple II, the only people who could acquire a personal computer were those who knew where to buy all of the components and how to assemble them. Assembly often times required soldering. Talk about high barriers to entry.
Apple has risen to become the world's most profitable company because it embraces convention and eschews configuration wherever possible. Apple pioneered the first personal computer hardware that people couldn't physically open or configure. And just as importantly, Apple makes software design decisions for its customers so that they don't have to. It turns out that people want computers that "just work." They don't want to deal with hundreds of settings and options. iOS represents the pinnacle of convention over configuration in the mobile OS market, where users cannot access or manage the OS’s file system or processes in any significant manner.
For most of Apple's history, it was the loner in the industry in its pursuit of convention over configuration. Most of the rest of the industry valued openness, flexibility, and configuration. It wasn't until the mobile computing revolution of the past few years and Apple's extraordinary corresponding rise that the industry began to actively push convention over configuration. Microsoft in particular has changed its views on the issue. The transition from Windows 7 to Windows 8 marks a very large swing away from configuration towards convention. Looking forward, it appears that most consumers will compute how Apple and Microsoft allow them to.
Although Android is quite flexible and open-source, it’s quite apparent that Google is actively working to mitigate some of the major shortcomings of configurability. The Nexus line is intended to encourage Android OEMs to converge on Google’s vision for Android.
We can see a similar shift in software development itself. Abstraction in many ways favors convention over configuration. Why should developers worry about memory management, object models, file storage, and application distribution when Apple/Google/Microsoft can handle it for them? Why should developers worry about API management when Mashery can manage APIs for them? Why should developers worry about infrastructure when Amazon can build, operate, and scale it for them?
We can see the power of convention extend into web services as well. Although the Internet is hailed as extremely democratic, capitalistic, and thusly competitive, we've seen that most web-native businesses tend towards monopoly because of network effects and economies of scale. Amazon will be the Walmart of the 21st century, and no one stands a chance of stopping them. Google has owned search in every country except those where the government actively worked against them (Russia and China). eBay owns peer-to-peer physical goods auctions in virtually all markets that it competes in. These companies are the natural convention for the general public. "I go to Google to search. I go to Amazon to buy things. I go to FaceBook to share with friends." What percentage of the general population actually uses Path or Diaspora in place of Facebook?
Google Glass, the pioneer of one of the major new computing form factors, is extremely locked down. You will use it only in manners and conventions that Google deems acceptable (this is arguably a good thing to protect privacy). As we move into the hyper-mobile era of computing in which computers are everywhere, expect convention to continue to overtake configuration in most consumer and business markets.