Where am I wrong?
Such as?
Personally I've taken to using Swift basically in every use-case where I can, largely because it's so nice to work with. It strikes a very nice balance between productivity (lack of tedium) and strong compile-time guarantees of correctness.
From my perspective, there are a few obstacles preventing Swift from achieving wide adoption:
1. Tooling and support outside Apple platforms has a long way to go. The story is better than it was even a year or two ago, but when compared to Rust, for example, Swift is massively lacking in this area.
2. Swift is still viewed as an iOS-only language. Even though there are now mature libraries for things like writing a webserver, and it's quite possible to write software for Linux using Swift, the developer perception is not there, and thus adoption is slow. This contributes to the lack of tooling and support.
3. Performance needs some improvement. ARC and copy-on-write are great for writing correct code easily, but they lead to some serious and sometimes unpredictable performance cliffs with Swift. There is a lot of low-hanging fruit here, but this needs to be addressed before Swift could ever find a place as a systems programming language for example.
So I would not quite say I'm bullish with respect to Swift's chances of breaking out as a general purpose programming language, but objectively speaking I would say that all the problems preventing Swift reaching that state are solvable problems, and Objective-C compatibility has little to do with it.
curl -s <https://packagecloud.io/install/repositories/swift-arm/relea... | sudo bash
sudo apt-get install swift5=5.0.2-v0.4