Wow, I had no idea Rosetta Code existed and as someone who loves linguistics (and can struggle knowing how to convert one computer language to another), I think I may find this really handy. Thank you!
Rosetta Code is useful, but many of the examples are horrendous. It's most likely because an example from one language is extrapolated into others without always considering if that language or community has its own way of accomplishing something. Occasionally I still use it, and it's good when you're a junior, but I think devs should try to move beyond it.
And the other issue is the more than one way thing, you need "flavors" of different languages.
And once you get past that, what is really needed is a standard reference implementation of a website, IO pipelines, network code, ssh libs, and tons of other things. Rosetta has a lot of crappy algorithms and paper-thin examples.
It's a good idea, but I think Stack Overflow could have implemented something far better, at least for the main languages they had armies of karma seekers for.