I think there are restrictions to forbid apps from arbitrarily forcing users to have an account. Apple can request in some cases that there is a way to use you

I think there are restrictions to forbid apps from arbitrarily forcing users to have an account. Apple can request in some cases that there is a way to use your application without any account, or that you provide a signup form inside the app. There are exceptions, but I assume you have to justify them to Apple aside from "I don't want to pay your fees". Basically, the rules are a bit more complex I think and they cover a number of potential loopholes.