... Apple's approach of maintaining the same external casing and largely unchanged internal components in its 'S' models limits the innovation that can be offered, making consumers far more likely to look around at competitor products in 'S' years ...
1. Most consumers in the U.S. (Apple's largest market by sales) are on 2-year contracts with their carriers. Therefore, every year, only about half of us are realistically in the market for a new iPhone. Only off-contract subscribers and first-time smartphone buyers have the freedom to "look around" without facing a heavy early termination fee. Apple knows that most people will not pay the ETF every single year, even if there were a radically new iPhone every year. Hence the "tick / tock" model releases.
2. Those of us who are on the even year contract cycle have enjoyed an extra year of "freshness" in terms of exterior iPhone styling. I bought a 3G in 2008 and it still looked up-to-date in 2009. Same with the 4 I bought in 2010. Looked up-to-date right up until September 2012 when the 5 was released. (No, looks aren't everything, but the common tick-tock exterior design helped maintain the resale value of even-year iPhones.)
3. Apple's ecosystem adds huge value to iPhone, and also helps to encourage repeat sales. If you spend a few hundred bucks on apps, music, and movies in the Apple ecosystem over the years, you're going to be less likely to consider switching.
... Ritchie points to the range of rumors circulating around potential new products from Apple, and says that while all are unlikely to be true, "breaking patterns and challenging expectations is just one way to solve that problem".
Some time in the near future, the "problem" will go away because we'll reach a point where iPhone and its Samsung copies have all achieved fantastic battery life, hardware features, thinness, lightness, screen resolution, CPU power, low cost, and anything else that will be appropriate for a smartphone. That's when the pattern will really be broken. Happened with iPod, and it will happen with iPhone.
Yes, there will continue to be technical advances ad infinitum, but they will mostly be driven by increasing bandwidth as carriers move from LTE to "real 4G" and beyond. In the meantime, over maybe the next 5 years or so, the tick-tock strategy should work just fine for Apple.