Kotlin is a prime example. You have to download the vendor implementation. There's no way to bootstrap. It's horrible from a tooling perspective.
Any single-implementation language inevitably degrades to the point where the implementation becomes the specification. Shortly afterwards, people can only use the language if their tool chain, operating system, etc. closely match the understanding of the language authors. That's a bad situation to be in.
I don't see how the bootstrapping problem is linked to multiple implementations.
> Shortly afterwards, people can only use the language if their tool chain, operating system, etc. closely match the understanding of the language authors.
Perl, well-known for being an iffy language to install and running on a restricted set of OS/architectures.
Any single-implementation language inevitably degrades to the point where the implementation becomes the specification. Shortly afterwards, people can only use the language if their tool chain, operating system, etc. closely match the understanding of the language authors. That's a bad situation to be in.