No company has done as much damage to the perceived value of software, and the sustainability of being an independent developer, as Apple.
Not that other companies wouldn’t have done the same thing — they would have. It’s just that Apple was the successful one.
It’s resolutely the fault of us as consumers, and it’s actively encouraged by the App Store.
Matt raises a few good points, however, I also tend to feel that developers themselves are partly to blame. For example, many years ago App A launched at $9.99. A few months or years later, competing App B comes along, but it starts out at $4.99. After a while, App A starts a 50% sale (and often doesn’t raise the price again). App C comes along at $0.99, followed by App D, which is free with in-app purchases. That’s the trend that I have seen for many of my favourite apps. Some developers stay strong, however — The Soulmen with their Ulysses [iOS/Mac] for example. The Mac version costs $44.99, while the iOS version is only $24.99, and both versions have nearly identical functionality. They can be used as standalone software too — there is no need to use them both. We’re not even getting into developer sustainability here — cost of living in some countries is much higher than in others. Some do this is as their full-time job, others as a hobby.
The one thing that I still expect Apple to do, is to add an upgrade pricing mechanism, which would greatly benefit developers. I’ll gladly pay for upgrades, but I am probably in the minority. Unfortunately.
At this rate, we might not have a lot of quality software to choose from in the future…