[simonh]

iOS and MacOS are really just flavours of the same operating system. That includes most of their system services, core libraries such as graphics primitives, sound system, network stack, data persistence libraries, etc. Even the higher level application frameworks have a high degree of commonality.

When you run an iOS app in a simulator on a Mac it’s not like running a virtual machine under VMWare, it substantially uses the native underlying MacOS libraries directly, because they are the same.

To do that on Linux or Windows Apple would have to port almost all of their operating system services, application frameworks and GUI layers and XCode from the Darwin OS core to Linux or Windows. That would be a truly massive undertaking.

All they are asking is that if you want to use their software, as a user or as a developer, is that you buy it.