John Gruber:

So why aren’t those who are criticizing Apple for taking a 30 percent cut of subscription revenue criticizing Amazon? My theory: everyone understands, intuitively, that the Kindle is a closed proprietary platform; but many people view iOS (incorrectly) as a platform like the Mac or Windows, where third parties are free to do what they want.

The root cause for so much of the subscription ruckus, I think, isn’t that 30% number — it’s that Apple pulled the rug out from under some major apps after the fact. And unlike nearly every App Store rule change in the past, this is a major change that developers couldn’t have been reasonably expected to anticipate, and it’s not based in any practical need for the health of the Store or the platform (malware, abuse, etc.).

Developers are being shown that their apps — and their months or years of hard work, and in many cases, their entire businesses — can be yanked by Apple’s whim at any time for reasons that they couldn’t have anticipated or avoided. This invokes fear and anger from many, and I think most of the “30% is too much” arguing is a misdirected side effect of this frustration not at the number itself, but at the seemingly arbitrary and greedy nature of the rule.

Gruber is right to point out that Amazon’s terms to publishers, generally, are far worse. And their corresponding proprietary platform — the Kindle — doesn’t have much1 of an app platform.

But unlike Amazon, Apple is pushing iOS as a relatively “open” platform, where “open” means the ability to create and run software by people other than the platform vendor (Apple) itself, and the associated ability for developers to base significant businesses on this market. Apple’s own rhetoric has encouraged hundreds of thousands of developers, big and small, to put significant resources into making iOS apps. Amazon has never implied on any serious level that the Kindle should be considered such a software platform.

The extremely low barrier to entry for the iOS market, especially with its low cost and lack of much of a required business relationship with Apple, further differentiates this situation from that of “more proprietary” platforms such as video-game consoles. The more proprietary platforms also usually have some degree of pre-approval and lack any significant denials or removals of formerly approved software.2

Gruber’s main points on the subscription issue are valid: Apple doesn’t need to follow anyone’s requests or do what’s convenient for anyone but Apple. And there’s a clear business case for them to try to extract as much money as possible from their entire ecosystem.

I agree with Gruber that it’s incorrect to expect iOS to be as “open” to developers and their businesses as Mac or Windows. But I also think it’s reasonable to expect Apple to adhere to some common-sense standards on how they conduct the massive platform that many of us — upon Apple’s invitation to do exactly this — invested heavily in.

A very reasonable expectation, I think, is relative stability: that our apps, once approved, will continue to be permitted indefinitely unless there’s a justifiable reason to prohibit them later.

And if Apple breaks that expectation by changing an important rule in a way that we think isn’t justifiable, it’s perfectly reasonable for us to complain about it as loudly as possible in order to effect change.