The problem is not the Apple tax. It's apple app store, they should be able to charge the commission fee they wish. The problem is not allowing other app stores/sideloading on iOS.
But isn't that what makes it a tax? I'd be happy to pay a price in exchange for Apple reviewing software for quality and security, but that's a service I can choose to either buy or eschew. Whereas a tax is something I'm forced to pay.