[ryanbrunner]

> I don't see why for any non-vertical domain, in theory, we couldn't manage the complexity of having just one huge standard library available to Java, C#, Python, Ruby, etc.

I think you can look to pre-existing multi-language ecosystems like the JVM, .NET, etc. that show that this isn't always the greatest idea. Languages have different idioms and ways of approaching problems, and using a standard library geared towards a stateful, OOP language is going to feel out of place and awkward in a functional language (and vice versa).