Earlier quoted context omitted.
If they just had a proper cross platform standard library and package manager it might be more successful, it is a pretty cool language. But the north Korean esque closed apple ecosystem makes that impossible, all of that is intentional.
Why is it not better for Apple to make Swift truly cross-platform? Is it just that the maintenance cost is not worth it? Or would it threaten its ecosystem in a way that I don't understand? It would seem that making Swift cross-platform would make Apple's ecosystem more accessible to developers. The barrier to entry would be lower if developers only needed to learn the APIs and not a whole new language and its toolin…
The greatest barrier to entry is XCode. It's archaic, impossible to extend, and has a very wide surface that would overwhelm any development team.
(Java works fine on macOS, but developers want to deploy to iOS.)