Even 600$ is quite a bit of money for a small open source project, especially outside of first world contries. You cannot except every single open source developer to buy somewhat overpriced hardware just to publish it in one platform.

None of the other desktop/mobile platforms require specific hardware , Windows/Linux/Android can all be virtualized/cross compiled to. The only reason you cannot cross compile/virtualize from other platforms is because Apple doesn't want you to. Its possible, there are projects that allow you to do so, but it violates Apple's license.

https://github.com/tpoechtrager/osxcross

Also its not fair to compare hobbies like photography or music to programming, you don't need any physical hardware other than a computer for majority of the cases, except testing (even that can be done somewhat reliably by virtualization), and when you are artificially forced to buy hardware just to publish to a platform.