Even when their AppStore is mandaded to all your hardware by DRM with you not having any choice of opting out? You want all your possible business speech, products and content you consume dictated by a corporate decree with no accountability?
The app store is a closed environment where they can dictate some terms. But don't forget that the developers PAY THEM to use it, and as such their terms cannot trump the consumer laws that exist to protect against abuse.
(By the way, "my shop, my terms" have already faced legal scrutiny, some of which were found to be illegal - popular judgements include that shops cannot refuse to serve people of colour or gays.)
Those “popular judgements” were because the laws on discrimination say so. There’s no law saying a store has to sell what they don’t want to. If Target (for example) decides to stop selling Pampers because they don’t like the name (for whatever reason), that’s their choice.