Not only excellent library support, but also a large array of productivity tools ranging from superb IDE, static code analysis, build+dependency tools, great Continuous Integration, etc.

Haskell also has (pretty) good library support (talking about "batteries included")

there are also a lot of libraries for the .net platform outside the framework itself , too

It's mainly a bad impression then, that w/ Python every document is to the point and with Java an outsider can't do anything?

I'll try to build my next project on top of github.com/codahale/dropwizard