Hasn't a language feature failed if even experts disagree on it? How would lay developers ever use it? This is not an algorithmic nicety; it's supposed to be

Hasn't a language feature failed if even experts disagree on it? How would lay developers ever use it? This is not an algorithmic nicety; it's supposed to be second nature to write and automatic to read. And it seems weird to omit Swift from this comparison, since Swift seems to have the most user-friendly (but incomplete?) implementation of move-only types.