That's why parents had to sue them to get refunds on fraudulent in-app purchases as children were scammed and manipulated into tapping buy buttons again and again. That's why Macbook Pro owners had to sue them again and again to address product defects. That's why they're being investigated in both the EU and US for abusing their platforms. They even officially had a rule for iOS developers that threatened against talking to the press.
If you run to the press and trash us, it never helps.
YMMV on that - personally, I've gotten pretty decent support for my Apple hardware. For example, in one case, they completely replaced a laptop that had gone out of repair support with a new model that was supported. I don't like the butterfly keyboard, but they replaced it twice and gave me a third-revision model that has worked fine since.
In addition to macOS, I use Linux (in a VM) and Windows (both VM and native) on my Apple hardware, and they all work fine.
I think Apple tries to distinguish between apps that provide access to content which you subscribe to (so-called “Reader” apps) versus apps where the service is the app itself.
If the service is the app itself, then they want all apps to be sold directly through the App Store. If the app is a Reader for a content subscription, then they allow selling the content subscription separately.
I’m not sure it’s evenly enforced, but I think that’s their intent and stated policy which they are trying to enforce here.
> Apps that operate across multiple platforms may allow users to access content, subscriptions, or features they have acquired in your app on other platforms or your web site, including consumable items in multiplatform games, provided those items are also available as in-app purchases within the app.
Basically Apple says if you're offering a multi-platform service - which this e-mail client clearly is - then you must provide the option to buy the service in the App using apple's in-app purchase system.