Here's the thing, even considering the fact that the report says that Microsoft has "offered" to remove the subscription options from the app, we're hearing one biased side of the story. They could have done that, but still left in a link that directs you to the site where you sign up, which is against Apple's Terms & Conditions.
Whether you agree with Apple's stance on subscriptions, here's the deal: when a developer signs up, they agree to the T&C. If they think the game's unfair, they don't have to play. Apple says "Here, you can tap into our massive user base, but you have to follow these rules. If you don't want to follow the rules, then that's your choice, but we won't allow your app in our store."
It's very simple. There are workarounds in place, though they're not necessarily elegant.
The market should decide here, and it has. Until developers start jumping ship and Apple starts losing revenue, it'll stay like it is.