I somewhat see it being good as a:
One distribution channel.
But why? I doubt but this seems as if Apple wants to hold ALL the data. Why?
This loophole thing leads me to a question:
Does this imply that people cannot sell their content without Apple interfering in their revenues? Why should Apple be paid 30%? Is it just because it's on the App store?
Here's the crux of the problem: Because Apple wants a consistent experience on the App Store for distributing apps, that means a single source of data for the App itself. That costs money, and Apple is determined to make it so that it can pay for itself in the long run. The 30% cut pays for general operating expenses of the App Store (hosting, billing, etc).
The catch is this: You can't take 30% of nothing. If I post a free app, then I'm using Apple's generosity in paying the hosting bills. Now I monetize the app via ads, subscription fees, micro-transactions, and so on. It's a valid monetization strategy,
but it completely cuts Apple out of the revenue while still putting them on the hook for hosting. So, in response you see iAd and in-app transactions in order to tap into that revenue that they were previously being left out of. And this money is funnelled into the part of the business that runs the App Store.
The big difference here is that Apple used iAd as a carrot to get developers using advertising that Apple could get a cut of. With the subscriptions, they are using the stick. People like carrots more than they like sticks.
And yes, an answer here is that you can allow side-loading of Apps and get people to use their own hosting and pay for distribution themselves. However, this also opens up the platform in a way that people are not used to. And by people, I mean carriers/etc. Think of the number of zombie PCs out there spewing spam, DDoS attacks, and trying to replicate themselves. Sideloaded apps give a similar foothold on the mobile platforms, and it is something that honestly scares the crap out of the carriers. They have been fighting open platforms on their networks tooth and nail, because these sort of zombie devices produce a ton of traffic which they just can't handle due to bottlenecks at the last mile.
Now, Apple can provide a signing service where you still have to meet X guidelines and you pay a fee for that service, but you can cut Apple out of your revenue stream in exchange for paying for all the costs of hosting yourself. The carriers might agree to this, but it will definitely fracture the iOS experience, somewhat. This is a trade-off that Apple may not be willing to make yet, although it may have to do something here in the future.
Again, one-size-fits-all is not fitting all at this point.