This is an overly simplistic view. We're not talking about physical stores and inventories here nor are we talking about a perfect uniform widget.
To indulge you though:
- tenant pays no rent to the property owner in this scenario if they make no sales directly from the property (Spotify is a free app with a free ad-supported tier in which case Spotify pays nothing to Apple)
- tenant can still leverage the "traffic" from the property owner's mall to promote its services (Spotify is able to reach its customers via the App Store even with the free app and free tier, placement in rankings becomes a source of lead generation for them without any fee per lead)
- tenant is able to sell widgets elsewhere and then have their customers bring them into the mall to enjoy without any charge (Spotify can still sell subscriptions to its service outside of IAP without any decrease in experience of the service)
- tenant had its widget factory subsidized by the property owner (Spotify was able to leverage Apple's development stack to create their app and the OS on which it runs)
- property owners cost to operate their own "rent free" store is equal to the rent they are charging the tenant so at a $0.75 profit they also had $0.75 in costs for facility upkeep and management effectively bringing their profit to $0 (Apple's App Store is a zero sum unit, the revenue brought in from App Store fees is equal to the costs Apple incurs in running App Store*).
Apple has not violated any laws and is not operating in an unethical manner. Sure, Spotify wants to be able to use Apple's distribution channel without paying for it, who wouldn't, they won't gain any (more**) ground here though.
Flip this around though, let's take a look at two direct scenarios though (directly, not using weak metaphors)
1) Apple drops all fees on subscription in app purchases. The next day every App becomes SaaS (software as a service). Now you can pay for my $1.99 Kardashian themed voter guide in 12 easy monthly installments and Apple doesn't see a dime from App Store (but still has to shoulder significant costs of infrastructure).
2) Apple allows redirects from App Store to external subscription pages. Again, everything goes SaaS with a simple link to purchase from the developer's web site. Again, Apple continues to incur all costs while losing the revenue stream that supports the process.
This wouldn't be universal, there would continue to be companies that do the right thing and sell their apps in the traditional method but there would likely be enough people trying to game the system to have a real impact on the viability of the App Store and none of us want App Store to die. The method Apple has suggested of dropping fees in year two and beyond is a good compromise. It prevents the scenarios above while recognizing that Apple's costs follow a sliding scale with time for subscription services. There are still costs in year two and beyond (any App that's going to hold a subscription audience is going to receive updates and still occupies storage, takes processing overhead, requires bandwidth for delivery, audits of updates, share of the costs of continued development of App Store platform etc...) but are likely disproportionate to perpetual license scenarios.
* In aggregate although I realize the sources of those costs and revenue are not evenly distributed. I also see Apple's revised year 2+ subscription model as being a response to those discrepancies.
** given that Apple has already dropped fees on subsequent years of subscription.
