I agree with the gist of what you're saying, but I don't think I'm perceiving it as causing as many problems as you do. That being said, I agree that requiring all subscription apps to cost money isn't a bad idea. Instead of pulling a cut from every subscription payment, they simply mandate that any app that offers a subscription service is required to be some actual price, maybe a variable price based on the cost of the subscription. That would be a very friendly alternative from Apple.As you said below, there isn't a perfect analogy for this, so we're all trying to work with what's best given the circumstances.
Apple making money off of sales through the app store is perfectly kosher. If it came down to it, I'd rather they charge something like 99 cents for service apps like Netflix, Hulu, and Spotify, and take 100% of the profits from that sale because they all make their money through the sub fees anyway.
But think of what would happen if everyone started following Apple's direction on this, that because someone is running a service on their platform, they're entitled to a cut of the profits. It'd end up with only 1st party apps being worth a damn in comparison, because they wouldn't have to worry about any extra overheads, and can set aside more to improving their service while still turning a heavier profit, or the 3rd party apps would have to raise their prices to compensate, and then wouldn't be able to compete with 1st parties on price. The end result would be entrenched 1st party services being able to bully and control the market, leaving the only competition among vertical platform owners.
What Apple's doing is more than a bit anticompetitive. But since there are workarounds, and Apple doesn't absolutely force the issue, it's not really worth doing anything more than arching an eyebrow over.
It's a good example, because Steam does give away things for free, and they handle far, far more bandwidth than Apple does. It negates the argument that these apps are mooching off Apple's good graces, taking their expensive bandwidth by hosting the app without giving anything in return.
For one thing, the amount of money Apple spends on bandwidth to host these apps probably costs them mere dollars. It's certainly not eating into their profit margin enough to justify taking a 30% cut off all sub fees on iOS. Think about all the demos and free apps people download that don't provide Apple with anything. If it were truly so costly, Apple wouldn't offer them.
It's the argument that Netflix, Spotify, etc. are stealing from Apple that I take issue with. To clarify, I'm not saying Apple doesn't deserve to turn a profit off the App Store. They do. They provide an excellent service themselves. But there is such a thing as taking too much.
That said, I've been doing some research, and I can't actually find verification that Valve doesn't take a cut from every subscription payment made through Steam. So maybe they aren't such a great example after all. Though that was just a short search, the information doesn't seem to be readily available.