Language coherency without business critical libraries, tooling and support for existing use cases, doesn't help much regarding language uptake.
I like Rust, yet I would be very masochistic to drop the C++ tooling support to write native libraries to plug into Java or .NET applications, and drag our customers and team alongside, just in name of coherency.
I have seen too many coherent languages fail to survive the adoption curve, because their communities failed to focus on the essencials to actually adopt them.
Go and Rust on the other hand are new enough to have coherency taken as a whole.