It's not like you need to ask a language community's permission to build your own thing in that language. Before Rails the Ruby community was very OO focused. Rails isn't very OO to be honest. It tends to used lots of composition and duck typing. You can see the major shift in the libraries before and after rails.

The question is, could somebody build a strong framework for web applications on Go? Maybe, i'm still learning the language myself so i don't know. Just because the language designers don't like it, doesn't mean that somebody won't come along and do it.