Hmm I only have an iPod 4 and that only goes up to iOS 6. Is there any site where you can see how big the market use is for each device? Is it really only 4% using this old devices?

Its just because no one want to support iPod4. 256Mb is RAM is the main reason. This still leave iPhone4 as problem device.

The upgrade rate for iOS device owners is very fast. Usually after the first month of an iOS update being released the usage is already up to about 70%. Apples own recommendation is that you only support the latest two versions. Also iOS 7 was such a big departure from previous OS versions it is just too much of a ball ache for developers to continue supporting older versions.

With Android it is a little different because there are so many custom versions of the OS supplied by many different vendors that they take ages to update, so you have no choice but to support lots of older OSs but with Apple its something that developers don't really have to care about.

Unfortunately for you it means that your iPod 4 is now just a novelty retro mp3 player.

It's 3 years.... an eternity in smartphone terms.

Three generations in three years is still planned obsolescence, since the devices are capable of working for far longer than that. A big part of Apple's marketing strategy hinges around the idea that it's not cool to have a phone that's the latest one.

What you observe is just a symptom of the manufacturer trying to sell new devices every year. Read http://en.wikipedia.org/wiki/Planned_obsolescence if you'd like to know a bit more!

Nonsense. You can say what you want iDevices (locked down, lagging in features, etc) but they are far better than Android at supporting older devices. Each new iOS version is typically supported on devices up to 3 generations previous.

...and makes those older devices run worse, slower, buggier, crashier than the previous iOS versions... encouraging you to upgrade because your old device is now worse performing than when you bought it.

Although that's not much better/worse than the upgrade cycle for Android which can be anywhere from 'none' to 'one' despite the hardware being able to deal with it and relies on the whim of the carriers as much as Google.

And when Google goes and does something like this, where they stop providing security updates when most of the world isn't on latest version they'll support... well... I have no words.

On the upside it continues to reinforce my position about Android being a massive pile of shit which I wish would just die... so, that's something I guess?

There is another very strong reason I'm surprised was not mentioned.

Just like the game console vendors, Apple has requirements that software developers must be running against a current version. Apple currently requires that all apps uploaded to the App Store must be built with iOS 7 SDK.

Don't worry, today's iOS 7 requirement is going away...

Starting in 19 days (1 Feb 2015) all applications need to build against iOS 8 and include 64-bit support. If you haven't updated yet, you either need to publish it in a hurry or update your build chain.

There is another very strong reason I'm surprised was not mentioned.

Just like the game console vendors, Apple has requirements that software developers must be running against a current version. Apple currently requires that all apps uploaded to the App Store must be built with iOS 7 SDK.

Don't worry, today's iOS 7 requirement is going away...

Starting in 19 days (1 Feb 2015) all applications need to build against iOS 8 and include 64-bit support. If you haven't updated yet, you either need to publish it in a hurry or update your build chain.

Yes, but you can build against the iOS8 SDK and still have iOS6 as your deployment target.

Also, to clarify in case anyone panicked, the 64-bit requirement on Feb 1st only affects new apps, updates to existing apps have till June 1st: https://developer.apple.com/news/?id=12172014b